Hello Wilgert,
The MAC-address on the label correspond with the Etherport (when you connect a cable of the AP).
The 2nd MAC-address, which you saw in Inssider, is related to the wireless radio in the AP itself.
You can find the 2nd MAC-Address under the "AP Mode"-Tab.
This address is used when you configure a repeater and AP's for example.
It seems the radio is still working fine and is reachable.
Regarding your issue with the connection, when you tried to connect to the AP by cable,
did you take care that you were in the same subnet with your PC's/Laptop's as the reset WAP (192.168.1.0/24) ?
When you tried to access it, like 192.168.1.200 as ip-address and 255.255.255.0 as subnet mask, did you try to ping the WAP200?
Was the ping working? but you just couldnt connect to the web interface of the WAP?
When the ping to the device works but you cannot acces the web interface,
I assume the web server of the device got damaged during the firmware upgrade.
If you cannot ping the device either, more troublehsooting is needed.
Regards,
Daniel