Having setup a ProtonMail-Account, together with the needed Bridge, I find that the refresh and general receiving of messages does not work. Once I get the Mail at ProtonMail it also arrives at Thunderbird, however it does not arrive at eM. Using Refresh also does nothing at all. However, when I use the Diagnose tool on the ProtonMail-Account under Account Settings I receive the E-Mail immediately, but not with any other option. I would be thankful if there is a solution to this, as that account is my main-mail-account.
Do you have a POP or IMAP account ?
The bridge makes it IMAP.
Ok. Suggest to maybe checkout the Proton mail SSL Connection issues link below. May help you.
Bridge connection issues with Thunderbird, Outlook & Apple Mail - Proton Mail Support
Also i see that Protonmail is (only officially supported) on Microsoft Outlook, Mozilla Thunderbird and Apple Mail, so may not work correctly with other email clients as per the Proton mail knowledge base.
https://protonmail.com/support/knowledge-base/imap-smtp-and-pop3-setup/
I found another thread on setting up Proton mail with eM Client where another user got it to work. See this link - ProtonMail Bridge and New Account Configuration - Frequently Asked Questions - eM Client
Okay, I will look through them, thank you!