Yeah, I picked up a cold in late January too, after a few days in Kaohsiung. Quite an odd one as well – really just an extremely runny nose, congestion, and feeling a bit rough for several days. No real sore throat, not much of a cough, and no fever or loss of taste (although I should note that I ate Taiwanese food a couple of times, and even came close to enjoying it, so that’s a bit worrying). I don’t remember having a cold like that before, and I probably haven’t had a cold at all for a couple of years now.
I originally just put it down to a combination of the pollution in Kaohsiung at the time (it was noticeably hazy, but I’m not very sensitive to air pollution, and I’ve lived in China during winter and northern Thailand during burning season without any real issues), several days of not getting enough sleep, and a couple of nights of sleeping with the hotel AC on. This was at a time where I wrote here a couple of times about hearing fellow passengers on the train coughing their lungs up, and I’d also spent a night drinking with some school teachers who’d just come from their weiya, so perhaps it was just a run-of-the-mill cold I caught from one of them. 
I did think about doing a self-test or going to the hospital for a PCR test, but given that Taiwan was only reporting a handful of daily cases at the time, it seemed entirely implausible that I could have caught it if the numbers were anywhere close to reliable…and if they weren’t reliable, I figured there must be a lot more cases out there not showing up. In the end I just kept to myself for a few days and was extra-cautious about wearing a mask inside, and it resolved itself after maybe 3–4 days.
Just a regular cold, yeah?