Tubleweed while starting up: all filesystem suddenly "read only"

What can I do, I do not think the issue is hardware related. Happened after an update, but when using snapshots the same applies. Just gives a lot of error messages about config files because of the read only status and "please contact your system administrator". The system is an ASUS notebook with NVME disk. (Vivobook). Any hint avoiding me the work to reinstall the whole system would be greatly appreciated.