When translation is enabled for Shipping methods with "Hide non translatable fields on translation forms" enabled
(at /admin/config/regional/content-language) - which is typically what you want for UX when translating. then the configured settings of the hidden fields are completely wiped when saving the translation.
This means that even in the original language all settings are empty after saving the translation!
I guess it's because you have to select Plugin to be translatable, to be able to translate all the fields.
There must be something wrong in the code around the translation logic, which is missing to consider this setting.
I think this is at least major, if not critical, as you lose all the shipping configration without noticing it and in fact have a totally wrong (empty) shipping configuration after translation.
See above
Find the bug in code, where the "hidden" option from above is not handled correctly. Ensure that the hidden field values are preserved.
By the way, the issue could be mitigated if the shipping methods were revisionable, see ✨ Make shipping methods revisionable to track changes Active
Active
2.0
Code