All interim latest version updates are not always automatically pushed out (even when you press check for update) manually incase there is any problems that may arise for a specific group of users as per comments from eM Client. I think this is wise to do that. Please see two comments end of the below thread from @Michal_Burger (eM Client Support).
Automatic Updates? - eM Client
eM Client advised the recent versions of eM Client (did fix) any issues with the manual check for update as i have had a message come up in the last week or so to update which worked, but that doesn’t mean all interim versions will be pushed when manually checking.
To manually check anytime for the latest eM client interium updates, go to the version history page and download it manually which is what i do when i’m testing. https://www.emclient.com/release-history