Many thanks for solving this particular issue.
Yesterday I updated Cryptomator to V 1.4.3 and since then I can save my PDF documents properly again.
BUT: Unfortunately, I now have an even worse problem. Only today I experienced three Bluescreens caused by the Dokan Driver, cf. the attached screenshot:
Any hints how to solve this issue? With Cryptomator V 1.4.2 and Dokan I never had these issues.