Quick take
Use Frigidaire FPPWFU02 / PWF-2 or a replacement explicitly documented for that connected-filter family. Do not substitute PWF-1.
Correct replacement filter
Frigidaire’s GRMC2273CF support page explicitly identifies FPPWFU02 PurePour Connect PWF-2 as the replacement filter.
PWF-2 is not PWF-1
The cartridge family differs from FPPWFU01, so do not shop by Frigidaire branding alone.
Replacement interval
Frigidaire documentation recommends replacement at least every six months and references a 125-gallon standard amount for PWF-2.
Compatible alternatives
Any aftermarket option should explicitly support FPPWFU02 / PWF-2 rather than only claiming generic Frigidaire compatibility.