MQTT Some tag values stagnant

Ignition 8.0.17 server on site
Same version server in cloud that hosts various projects. The above site is the only one connected via MQTT. This system has been running for close to 1 year.
80 000 tags.
Random issue (and we have ruled out connection as problem) is that some of the tags just does not get updated in cloud. System would work perfectly, but then randomly without warning or any notification just not update a group of tags for indefinite time (hours to days).

4.0.6 is used for transmitter, Engine and Distributor. (this version is used because it does not have the wrong historical data issue)
Any version higher than this does exactly the same thing (if upgraded while it is happening)

Ignition’s answer (from Cirrus) is that we have to upgrade to latest Ignition version, so that we can use latest MQTT versions. this is a very costly exercise as the Ignition licenses needs to be upgraded to version 8.1, and then again to 8.3.x whenever that comes around.

i am hoping for a more elegant (and affordable) solution

Update … After 10h hours the issue fixes iteslf. All values updating again as per normal

Update
happened again yesterday, 29 days after previous occurrence.

Further, unable to connect more than one edge node succesfully. Values from 2nd edge node does the same thing, but from birth.