Constant smell, I could never figure out the source. I thought it was moisture under the Weathertech Mats, but that did not seem to be the issue. Hope it stays away now.
I bought an ionizor and changed the cabin air filter, that the dealer did not check. Ran ionizor with climate system off, then with heat on, again with AC on, both with recycled air and outside air.
Happy to report, smell is gone.
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Having the same issue, haven't used AC all winter, but the truck smells bad when I get in it. Had the carpets clean and detailed, no help. 2022 F150 limited.