Issues with Zwave communication

Hello,
My name is Serge and I am new on this forum. I am living in Belgium an Morocco. In Morocco I have a rent house where I installed a HA with Zwave devices.
I have a total of 40 devices, most of them Shelly pro 3, Pro 1, pro 2PM, mini 1 PM. I also have 1 Aeotec HEM8 a Nabu Casa controller and a HA green. The installation is running wel when not to heavily loaded. But from the moment that you trigger ALL-Off or All-on automations (by room, +- 10 lamps) the network get overloaded and it goes wrong. The first thing I found out was that it is almost impossible to calm the hem8. It always send more info that what you ask for. At this time I am sending the 3 power on a 400W treshold, and the voltages every 15 seconds. It seems to work however it still sometimes send power when there is less than 400W variation and can't figure out why. Any help appreciated...
A bigger issue are the Pro and mini PM. However I completely disables the reporting in the zwave JS UI and deactived all the sensors in HA, HA still ask for power data (that I don't use) and as it does'nt receive it trow a timeout and block the communication with other modules.
And my third main issue is with the 1PM mini, that are triggered by a automation. Node 72 (pro3) receives an input that triggers an automation. The automation toggles the lamp from 2 1PM mini node 093 and 094. From that moment those 2 nodes will start sending their status (true or false) more than 30 times in less than a second. The result is that the controller get jammed and loses control for several seconds...
If anyone has an idea how to solve this, it should be very appreciated.
Thanks a lot in advance.

You flooding network

Maybe try turning on/off in groups.

May also help to look at logs to see where things go wrong. It could be chatty device that ties up network creating issue or device with poor connection that great issue during this function