Pairing detects same Arduino device more than ones

I am using Sonoff S20 sockets with modified Arduino based fw. Recently I changed the firmware and also changed the name of each unit (Homey.begin(deviceName)). As I added a Capability I had to redo the pairing. First I removed the old devices, then I started the pairing. To my surprise all old device names (that were not available by that name on the network anymore, nor used in a Homey.begin()) were added to the pairing list again.
Then, in the pairing list I only selected one correct new device. But still all the others (those with the same IP-addresses) were added too. If I remove the old devices again, they are added again next pairing.

How do I get rid off the old pairing instances? Thanks again for your help.

Try uninstalling the Homeyduino app (and then install it again), perhaps it keeps some sort of cache.

Thanks Robert. I tried “Restart app” and that was already sufficient.