PMs dont send alerts to all addressees

We have been using PMS Uddeim plug in etc with CB for over 10 years now with no issues. Two days ago I updated to 2.5.0+build.2021.02.01.21.20.37 and since then some users do not receive alerts when a Private Messages are sent to them. Weirdly some do and others don't.

Of course have tried all the fault-finding I possibly can from switches in Uddeim (we are on 4.0) - you name it, even mail server logs to see whether messages were rejected, but they were never sent to begin with.

And yes once again I tried all the usual reasons it could be, Front end user switches, back end switches, both Uddeim and CB configuration, mail server issues, Joomla mail send etc...

I have now exhausted every conceivable reason - does anyone have any idea what it could be at all or what else i can try?

I assume you mean the email notifications within UddeIM? CB doesn't have any control over this. We just store the PM using UddeIMs API. I recommend posting to the below forums as we're not the developers of UddeIM and can't help you with UddeIM specific issues.

www.joomlapolis.com/forum/25-uddeim-plugin-and-component

Have you considered moving to CBs built in PMS functionality instead of UddeIM?

OK will do that but just be clear that this only happened immediately after the upgrade to latest version of CB - is there a link perhaps with that? There has been no change for 3 years to Uddeim install.

I don't see how updating CB could have any impact on UddeIMs ability to send emails. The PMS code was not touched in latest CB release.