F-Droid is like package maintainers for Linux distributions. You have to trust them if you want to use their pre-built binary. However, some app builds are reproducible. Check the doc for more info.

Of course, but v1.x only supported gocryptfs. Also, new encrypted file systems may be added in the future.

DroidFS can open existing volumes. Just click on the “+” button in the bottom right corner, then on the folder icon, and then select the volume directory.

To type with only one finger, there’s 8Vim.

:help i_CTRL-H

 or CTRL-H  Delete the character before the cursor (see i_backspacing                                                       about joining lines).

From a security point of view, it’s better to create a dedicated network for each of your containers, as apps won’t be able to communicate with each others directly.

You can even not setup networking at all and use UNIX sockets instead. However, back-end apps will need to support that.

Check that the certificate store of your device is up-to-date. Ensure it is also set to the correct date. If all is ok, check that your device resolves your domain to the right IP. If it’s correct, check that the certificate fingerprint you get from your device is the same as what you get from your working devices.

If all looks good, maybe you can provide the exact error by attaching the output of curl -v or openssl verify.

What about DroidFS?