probably worth reading the comments here ...
https://www.zobodat.at/pdf/OestZPilz_22_0211-0278.pdf
Doesn't that imply that the matter is not settled ... in a modern phylogenetics-based sense.

Suillus albidipes was described by Peck, and in association with Pinus strobus. It will be a North American indigenous taxon and therefore unlikley (but not impossible) to be the same as the modern concept of S. granulatus sensu stricto. That is implied under the comments on S. granulatus by Klofac when discussing Palm's description of S. neoalbidipes. Palm, back in 1984, considered the name S. albidipes had been widely misapplied (based on Singer & Smith I assume), and that might be true. However Palm's 1984 assertion that S. albidipes = S. granulatus cannot be endorsed without modern phylogenetic support, and that would seem unlikley. Indeed the Nguyen paper supports the view that North American taxa are different. It is a pity Nguyen et al did not say anything about Peck's taxon. So, in my opinion, the current status of the name S. albidipes remains uncertain. There are no iNat records, and I would simply make the name inactive, rather than creating an unproven and unlikely synonymy with S. granulatus.

I deactivated it.

There has been a strong tendency on iNat to add names simply because they appear on some list, and not because they are names in current use. That is a pity.