HUE Bridge with cures

I have a HUE Bridge with cures. First it was connected to the Ziggo Router / connect box with a fixed / Static IP address. Then linked to a TP-Link Mesh system again but now with a fixed IP address.
So far the Bridge has worked fine; with the Android App, Domoticz (which I run on a NAS), outdoors / remote Hue also worked. But…
Since the TP-Link mesh was not sufficient, I bought an Orbi Netgear and that’s where the trouble starts.
I cannot manage to properly connect the bridge.
Lamp 1 is on
Lamp 2 is on
Light 3 … sometimes (after removing the power) it flashes , but
sometimes not.
The router does provide an IP address, unfortunately cannot link a fixed IP address, but do not think it is a problem.
Frequently the IP address of the Bridge disappears momentarily from the “Attached devices” list.
If I enter the IP address of the bridge in the Hue App, it cannot find the bridge anyway

The remote control does turn the on and off

Now it wants the Hue bridge in question to control 22 lamps, with schematics and so on …
(and I don’t have a handy backup). A factory reset is therefore not really desirable because I have to reconnect all lamps.

I don’t know what to do anymore, I’ve been working on it for days, and my enthusiasm for Hue is fading a bit.
In the house is a new unused Hue Bridge. It is immediately found by the Hue App.
I have already tried that, but the 22 Hue lamps do not find them (!?!?!) Even when I switch them on (and then I can enter the serial number per lamp, but that will be quite a job that I cannot is waiting.

In short …
who recognizes this and has solved it how, 3 questions:
1-Does anyone know what I might be able to do to make the Hue Bridge work properly.
2-There is a reset option that retains the lamp data
3-There is a possibility to transfer the Lamp configuration from one Hue Bridge to another Hue Bridge
and for the future
4-Back up and restore of lamp configuration is possible

Kind regards,
Kees