soldering

Hi guys, so I bought nano elrs receiver from china BAYCK RC, which seems a copy of beta fpv receiver and now I’m confused and don’t really know how to solder it in right way. On YT there is only two videos from One man and 719. In the first case guy uses sp24s receiver which has 4 wires and...

I got 2 new AIOs from gepRC and trying to do soldering. Surprisingly all GND pads in 10pads cannot be soldered, but others are fine well. Is that GND pad different from other pads in general, like requiring higher temperature soldering?? Red circle pad is already burned out because I tried to...