Encrypting/decrypting very slow?

Hi,

I have tried to use Cryptomator in my W11 PC with G-Drive, but encountered difficulties of sometimes very slow response-times. So I tried it encrypting my Thunderbird e-mail folder on my local disk and it was as well very slow, not always but in some operations. This practically makes using Cryptomator to encrypt my e-mail system in-usable! This is pity, because Otherwise Cryptomator functions almost perfectly!
Any ideas?

BR,

Timo