eM Client not sync'g with ProtonMail

I’ve been using eM Client to read my Proton Mail for several years, no problem.

But, starting 3 or 4 days ago, I noticed messages I’ve read, moved or deleted using eM Client are not showing as read, moved (by a message rule) or deleted on my iPhone, iPad or on the online version of Proton Mail.

Changes made to my iPad, iPhone or via the online version of Proton Mail are sync’d and show up correctly in my PC’s copy of eM Client, but not the other way around…

I already “Synced” my PC’s email using the Proton Bridge application, three times, but it had no affect.

What setting change can I make that will force changes made in eM Client (messages read, moved or deleted) to appear on the Proton Mail side?