phc2sys sudden big offset

[2000david]

cat /proc/version
Linux version 5.15.0-105-generic (buildd@lcy02-amd64-054) (gcc (Ubuntu 9.4.0-1ubuntu120.04.2) 9.4.0, GNU ld (GNU Binutils for Ubuntu) 2.34) #11520.04.1-Ubuntu SMP Mon Apr 15 17:33:04 UTC 2024
ethernet:
01:00.0 Ethernet controller: Intel Corporation I350 Gigabit Network Connection (rev 01)
01:00.1 Ethernet controller: Intel Corporation I350 Gigabit Network Connection (rev 01)
01:00.2 Ethernet controller: Intel Corporation I350 Gigabit Network Connection (rev 01)
01:00.3 Ethernet controller: Intel Corporation I350 Gigabit Network Connection (rev 01)
sudo ./ptp4l -P -2 -m -i enp1s0f1 -H ./configs/gPTP.cfg
sudo ./phc2sys -m -s CLOCK_REALTIME -c enp1s0f1 -w -R 40
normally, it works well, but sudden with a big offset,1017, why it happened?

phc2sys[436265.216]: enp1s0f1 sys offset 107 s2 freq +53955 delay 20282
phc2sys[436265.242]: enp1s0f1 sys offset 36 s2 freq +53916 delay 20192
phc2sys[436265.268]: enp1s0f1 sys offset -264 s2 freq +53626 delay 19642
phc2sys[436265.293]: enp1s0f1 sys offset 0 s2 freq +53811 delay 20210
phc2sys[436265.319]: enp1s0f1 sys offset -21 s2 freq +53790 delay 20206
phc2sys[436265.345]: enp1s0f1 sys offset -51 s2 freq +53754 delay 20177
phc2sys[436265.371]: enp1s0f1 sys offset -23 s2 freq +53767 delay 20274
phc2sys[436265.396]: enp1s0f1 sys offset -99 s2 freq +53684 delay 20169
phc2sys[436265.422]: enp1s0f1 sys offset -92 s2 freq +53661 delay 20244
phc2sys[436265.448]: enp1s0f1 sys offset -78 s2 freq +53647 delay 20294
phc2sys[436265.474]: enp1s0f1 sys offset -140 s2 freq +53562 delay 20213
phc2sys[436265.500]: enp1s0f1 sys offset -116 s2 freq +53544 delay 20295
phc2sys[436265.525]: enp1s0f1 sys offset -101 s2 freq +53524 delay 20335
phc2sys[436265.551]: enp1s0f1 sys offset -228 s2 freq +53367 delay 20121
phc2sys[436265.577]: enp1s0f1 sys offset -132 s2 freq +53395 delay 20323
phc2sys[436265.603]: enp1s0f1 sys offset -168 s2 freq +53319 delay 20284
phc2sys[436265.629]: enp1s0f1 sys offset -173 s2 freq +53264 delay 20292
phc2sys[436265.654]: enp1s0f1 sys offset -210 s2 freq +53175 delay 20223
phc2sys[436265.680]: enp1s0f1 sys offset -187 s2 freq +53135 delay 20286
phc2sys[436265.706]: enp1s0f1 sys offset -166 s2 freq +53100 delay 20320
phc2sys[436265.732]: enp1s0f1 sys offset -476 s2 freq +52740 delay 19707
phc2sys[436265.758]: enp1s0f1 sys offset -181 s2 freq +52892 delay 20283
phc2sys[436265.783]: enp1s0f1 sys offset -170 s2 freq +52849 delay 20318
phc2sys[436265.809]: enp1s0f1 sys offset -205 s2 freq +52763 delay 20248
phc2sys[436265.835]: enp1s0f1 sys offset -227 s2 freq +52679 delay 20169
phc2sys[436265.861]: enp1s0f1 sys offset -209 s2 freq +52629 delay 20196
phc2sys[436265.886]: enp1s0f1 sys offset -191 s2 freq +52584 delay 20230
phc2sys[436265.912]: enp1s0f1 sys offset -171 s2 freq +52547 delay 20239
phc2sys[436265.938]: enp1s0f1 sys offset -127 s2 freq +52540 delay 20317
phc2sys[436265.964]: enp1s0f1 sys offset -429 s2 freq +52200 delay 19679
phc2sys[436265.989]: enp1s0f1 sys offset -120 s2 freq +52380 delay 20259
phc2sys[436266.015]: enp1s0f1 sys offset -91 s2 freq +52373 delay 20281
phc2sys[436266.041]: enp1s0f1 sys offset -129 s2 freq +52308 delay 20173
phc2sys[436266.067]: enp1s0f1 sys offset -91 s2 freq +52307 delay 20226
phc2sys[436266.093]: enp1s0f1 sys offset -23 s2 freq +52348 delay 20326
phc2sys[436266.118]: enp1s0f1 sys offset -66 s2 freq +52298 delay 20208
phc2sys[436266.144]: enp1s0f1 sys offset -32 s2 freq +52312 delay 20230
phc2sys[436266.170]: enp1s0f1 sys offset -14 s2 freq +52320 delay 20235
phc2sys[436266.196]: enp1s0f1 sys offset -269 s2 freq +52061 delay 19694
phc2sys[436266.222]: enp1s0f1 sys offset 24 s2 freq +52273 delay 20231
phc2sys[436266.247]: enp1s0f1 sys offset 68 s2 freq +52325 delay 20293
phc2sys[436266.273]: enp1s0f1 sys offset 34 s2 freq +52311 delay 20206
phc2sys[436266.299]: enp1s0f1 sys offset 59 s2 freq +52346 delay 20213
phc2sys[436266.325]: enp1s0f1 sys offset 87 s2 freq +52392 delay 20226
phc2sys[436266.350]: enp1s0f1 sys offset 114 s2 freq +52445 delay 20250
phc2sys[436266.376]: enp1s0f1 sys offset 128 s2 freq +52493 delay 20255
phc2sys[436266.402]: enp1s0f1 sys offset -12 s2 freq +52392 delay 20552
phc2sys[436266.428]: enp1s0f1 sys offset 116 s2 freq +52516 delay 20177
phc2sys[436266.453]: enp1s0f1 sys offset -1017 s2 freq +51418 delay 17880
phc2sys[436266.479]: enp1s0f1 sys offset 184 s2 freq +52314 delay 20193
phc2sys[436266.505]: enp1s0f1 sys offset 251 s2 freq +52436 delay 20294
phc2sys[436266.531]: enp1s0f1 sys offset 198 s2 freq +52458 delay 20193
phc2sys[436266.556]: enp1s0f1 sys offset 223 s2 freq +52543 delay 20193
phc2sys[436266.582]: enp1s0f1 sys offset 293 s2 freq +52680 delay 20316
phc2sys[436266.608]: enp1s0f1 sys offset 229 s2 freq +52703 delay 20166
phc2sys[436266.634]: enp1s0f1 sys offset 265 s2 freq +52808 delay 20223
phc2sys[436266.659]: enp1s0f1 sys offset 251 s2 freq +52874 delay 20185
phc2sys[436266.685]: enp1s0f1 sys offset 296 s2 freq +52994 delay 20264
phc2sys[436266.711]: enp1s0f1 sys offset 278 s2 freq +53065 delay 20235
phc2sys[436266.737]: enp1s0f1 sys offset 300 s2 freq +53170 delay 20304
phc2sys[436266.763]: enp1s0f1 sys offset 265 s2 freq +53225 delay 20237
phc2sys[436266.788]: enp1s0f1 sys offset 279 s2 freq +53319 delay 20291
phc2sys[436266.814]: enp1s0f1 sys offset 247 s2 freq +53370 delay 20228
phc2sys[436266.840]: enp1s0f1 sys offset 281 s2 freq +53478 delay 20313
phc2sys[436266.866]: enp1s0f1 sys offset 227 s2 freq +53509 delay 20231
phc2sys[436266.891]: enp1s0f1 sys offset 227 s2 freq +53577 delay 20272
phc2sys[436266.917]: enp1s0f1 sys offset 222 s2 freq +53640 delay 20278
phc2sys[436266.943]: enp1s0f1 sys offset 157 s2 freq +53642 delay 20211
phc2sys[436266.969]: enp1s0f1 sys offset 203 s2 freq +53735 delay 20314
phc2sys[436266.994]: enp1s0f1 sys offset 121 s2 freq +53714 delay 20188
phc2sys[436267.020]: enp1s0f1 sys offset 120 s2 freq +53749 delay 20229
phc2sys[436267.046]: enp1s0f1 sys offset 81 s2 freq +53746 delay 20189
phc2sys[436267.071]: enp1s0f1 sys offset 121 s2 freq +53810 delay 20312
phc2sys[436267.097]: enp1s0f1 sys offset 39 s2 freq +53764 delay 20191
phc2sys[436267.123]: enp1s0f1 sys offset 69 s2 freq +53806 delay 20292
phc2sys[436267.149]: enp1s0f1 sys offset 39 s2 freq +53797 delay 20271