I got support and it workded - here is the advise from Alex (Support from Bitwarden):
You will need to download the certificates at any time from the Bitwarden Cloud Web Vault. You will need to do it for both CA certs in the Chain, here is how to download the first Intermediate CA cert:
(two other pictures how to save the Certificate but I can only post one - will post them in a new answer)
Save the file as a DER Base64.
The Intermediate CA cert is the Cloudflare cert and the Root CA is the DigiCert cert, you need to install both following these steps: https://support.google.com/pixelphone/answer/2844832?hl=en
I hope this will also work for you! Let us know if it worked