MacBook Air mid-2019 - USB C port(s) not working in a strange way, possible malware

I have a mid-2019 MacBook Air (purchased in August 2020) where the two USB-C ports (on the left hand side of the body) alternate between working and not working. I use one port to charge the Mac, the other to use various compatible devices via a hub. So one such device is a USB DAC for music - the USB DAC (DragonFly) has a light which can indicate whether a (compatible) port it plugs into detects it.

I have researched this problem on Apple Mac forums, and it seems that this can and does happen to lots of Mac users. And if people are wondering whether I've followed all the usual official procedures in this situation, yes I have. I have tried soft and hard reboots, resetting the SMC and PRAM/NVRAM (many times!), software updates. I've inspected both ports with a flashlight - looks absolutely fine - and the Mac has never taken a knock on the port-side.

What is strange in my case is the mode and history of malfunctioning - currently just one port works, the other doesn't. By "work"/"works" I mean connecting the charging cable (with the other end connected to the powerbrick, which is plugged into AC power) to the port does not lead to the battery charging, even though the system detects the AC power source - I've verified this behaviour via System Information - Power section. So the port that currently does not work, was working normally up until early August 2024, when it suddenly stopped working. Then it alternated between working and and not working up to mid September 2024, when it stopped working completely. Then it began working again from late September onwards, and then stopped working completely about 5 days on Nov. 9.

You would think that a port which was genuinely damaged in some way would stop working and remain like that. A truly damaged component stays damaged - it doesn't suddenly come back to life. So this alternating behaviour makes me think about malware. I have read some articles, including a BBC article on malware delivered via compromising the USB-C charger, and the malware may be capable of remotely disabling either port by the attacker.

https://www.bbc.co.uk/news/technology-45139397

Mine looks like the genuine article - I purchased a new cable and charger from the Apple UK store around October 2023. This seems unlikely - why? -but who knows?

I'm also suspecting malware for another reason: Google searches sometimes trigger that popup where you're told that there is strange traffic coming from my IP address. I do use a VPN service for anonymity and disable tracking-based ads, but I'm not convinced it is because of the VPN.

If someone has had a similar experience please let me know.