What if Grout got Wet?

I thoroughly scraped and re-grouted my shower and applied some sealer (standard unsanded grout and Impregnator 511 sealer), but I am worried I didn't mix/stir the sealer enough or at all (my memory/recall is really sketchy nowadays). I am worried because I think some of the grout might be starting to erode or crumble away under squeegee action (this is about 2 weeks later). Grout was allowed to cure for ~48 hours before applying sealer, and sealer was allowed to cure for another ~48 hours.

So…in a worst-case scenario where sealer was completely ineffective (i.e. grout is effectively unsealed) and I have been dousing the grout with water for a week or so: 1) is the potential wearing away of the grout likely in this amount of time? and 2) is re-sealing the grout after letting it dry out for several days an option regarding fixing the potential issue, or will re-grouting be required?