If you want to record license plates at night, go for the A229 Plus, it has decent HDR while the A129 Pro doesn't. Some people say the HDR is not working all that well for them at the moment, but expect that to be sorted.
If you don't do much night driving, they are both good dashcams, and the A129 Pro records twice the detail at the front, but only half the detail at the back.
The A129 Pro is missing a few of the newer features, such as voice notifications and voice control, which are nice to have, but then some people turn them off anyway.
I think the A129 Pro has the faster wifi.
It is also the older, so has had all the issues sorted out, plus it has been voted best dashcam of...
I think most people would go for the A229 Plus, but there are people who prefer the A129 Pro image quality, and on USA roads, 4K can be a significant advantage.
I would probably look to see which had the best discount, and currently that is the A129 Pro, at least in my country.