The same issue I fixed last night, the aircraft firmware Version 1.11.01.50+ was not compatible with the camera firmware Version 1.11.1.50.
I tried reverting to 1.08 bin using the WM610_FC550_FW_DEBUG file trick and it worked but the video signal was still not working, I ran the same debug again with the WM610_FC550_FW_V01.11.01.50.zip link above and the video signal came back on after years of not working. Refer to the youtube video and the links in the chain
I tried reverting to 1.08 bin using the WM610_FC550_FW_DEBUG file trick and it worked but the video signal was still not working, I ran the same debug again with the WM610_FC550_FW_V01.11.01.50.zip link above and the video signal came back on after years of not working. Refer to the youtube video and the links in the chain