The US and China have been ramping up tensions in the straight of Taiwan, to a pretty extreme degree. How much of this is directly tied to the election is... unknown, but it is certainly being considered by both sides. These sort of things are inherently political, and we haven't seen this level of escalation since the 90s.
I don't think anything major is going to come out of this, but these sort of standoffs are dangerous, and a Taiwanese fighter taking down a PRC bomber would be really nasty. It really feels like most of this is just a ramp up for the benefit of the US election, with China wanting to show Trump as weak, and Trump wanting to look strong.