Fibaro dimmer /Z-wave issue

Hi everybody,

I have the following problem and I don’t know what to do anymore

Last week I installed 7 x Fibaro dimmer and 4 x Fibaro roller shutter 3
These are a replacement for my KNX system so all these modules hang together in my fuse box
Adding to Homey went without a problem.

Manually turning on, turning off and dimming the dimmers is also fine.

And now the problem,

If I make a flow where I control more than 1 dimmer, it goes wrong. 4 out of 5 times there are 1 or 2 dimmers that do not switch on or after a very long delay
This is random and a different dimmer every time.
Sometimes all dimmers come on, but usually 1 or 2 fails

If I then manually switch on the dimmer, the dimmer will switch on normally.

What have I already tried

-delay put between the cards (see picture above)
-homey placed in different places in the house, also in the fuse box 10 cm from the dimmers
-All apps disabled except the Fibaro app
-Homey reboots several times (also waited 15 min)
-The dimmers gave a HEAL command
-Flow made with 1 dimmer, that works great as long as it is only 1
-Flow made with 2 dimmers, then it goes wrong
-Scene activation disabled. Then it seemed resolved for a moment, but unfortunately

The problem occurs as

-A flow is started in which more than fibaro 2 dimmers are controlled
-A GROUP is switched with multiple fibaro dimmers
-A command is given via google home, eg “light on”

Of course I first thought of a reception problem, but since I can switch the lights manually, this does not seem to be the cause.

All zigbee devices (15 pieces) do it all perfectly.

I had quite a long 1 fibaro dimmer to test. Now made the decision to buy 6 more and it doesn’t work.

Who knows what to do?

sorry for my English. I mainly used google translate

The beta of thegroup app has the ability to ‘retry’ when a device fails. You might want to give that a go in the flow.

Not this doesn’t ‘fix’ the problem, simply hides the side-effects. You might want to double check that the device is correctly reporting its state. If someone else knows an actual fix, I would also be interested.