MQTT binding items just stop working at random

Using OH3 + mosquitto. Working well till days ago.
But now some, but not all! items (looks like esp based but not sure) just stop updates without errors in log just silence. My custom mqtt subscription in cli found data in. What can be wrong?

Example of “problem” thing:

Bridge mqtt:broker:main "Main MQTT broker" @ "MQTT" [ host="", secure=false, username="openhab", password="...", retainMessages=false ]
    Thing topic Ajax_Relay_1 "AJAX Relay 01" @ "MQTT"  {
        Type contact : contact "STATE" [ 
        Type number : temp "TEMP" [ 
Contact  Ajax_Relay_1_STATE  {channel="mqtt:topic:main:Ajax_Relay_1:contact", expire="1m"}
Number:Temperature  Ajax_Relay_1_TEMP "Температура [%.1f %unit%]" {channel="mqtt:topic:main:Ajax_Relay_1:temp", expire="1m"}

This item working well after last openhab restart for 10h and UNDEF now (latest 5h) and if I restart OH this item will work well but for a limited time.

Same happening here. I have 2 wallboxes reporting through MQTT. Data for either one of the stops updating at somepoint in time in Openhab. MQTT.fx still shows updates coming in from the wallbox.
I need to either restart OH or remove the things file and put it back in. I am on OH 3.1.0 M2

Please, add this info (about max_queued_messages) mqtt - Mosquitto: Outgoing messages are being dropped - Stack Overflow
somewhere in OH manual, this makes me crazy but helps