Issue with react-hook-form but only on branches, not on local environment

[levaiferencz]

We got this error today, and I cannot resolve it until now. hook.js:608 TypeError: Cannot read properties of undefined (reading 'split')
at S (index.esm.js:94:32)
at eJ (index.esm.js:1005:50)
at index.esm.js:1057:40
at oB (react-dom.production.min.js:243:482)
at oY (react-dom.production.min.js:262:46)
at e (react-dom.production.min.js:259:446)
at e (react-dom.production.min.js:259:343)
at e (react-dom.production.min.js:259:343)
at e (react-dom.production.min.js:259:343)
at e (react-dom.production.min.js:259:343)

We are using 6.4.0. version.