This is quite a tricky situation, especially for a board bought so recently! The symptoms with the HDMI and USB ports really do point to those connector issues you've identified. It's a shame there isn't a readily available, official repair channel mentioned for these specific boards, as something like this could easily happen to anyone. Hopefully, the manufacturer has some guidance for self-repair or a partner who can help, otherwise, you might have to get creative, maybe even asking a very tech-savvy
Granny for advice on delicate connector work! Good luck with the repair!