Blower Speeds run in reverse

Chevy Cobalt 2005, 188k. For the last week or so, the fan speeds were working in reverse. Settings 4 and 3 don’t work. Settings 2, 1, and 0 (off) work. I assumed it was the blower resistor. I switched that out, along with the blower motor (it slipped a bearing and had been making noise for a while) earlier tonight, but still has the same problem. I can only put the resistor and the plugs in one way, the mounting won’t let me flip them around.

Ideas? Will it get worse/lead to bigger problems or just stay like that?