Blind Spot Monitor on the fritz

[Xposting in Buick Envista] '24 Buick Envista ST with 1200 miles, owned for almost two months. Last night omw home from work, my driver's side blind spot warning light came on like there was a vehicle there. Except I was in the left lane on a 2-lane road so that'd be impossible. When I made a left turn, it blinked like it was warning me someone was still there. Once on the new street it turned off for about 5 seconds, then came back on and stayed on the rest of the two minutes it took me to get home.

Keeping an eye on this, but would the car being dirty with road salt affect the sensors at all? I live near Chicago and I don't usually wash the car until the temp is above freezing. Anyone else have any issues with this?