Minwax is one of the best on the market if not THE best. Sounds like
you either didn't clean completely between coats or you shook the can
some how and air bubbles in it. Here's what I did: First seal the
room. Machine sanded with coarse and then with fine and then extra
fine grit. Damp rubbed the bare wood. Sweep the wood dust up for
later use. Vacuumed and closed the windows that night. After sunrise,
when the moisture in the air is gone, open windows to vent. Let first
coat dry over night. Windows closed. open them in morning. Hand sand
with 000 or 0000 steel wool, again hand damp rub and vacuum twice.
Keep a roll of masking tape on your wrist so you can mark the nicks and
scratches. After the 2nd vacuuming, go back and paste those spots
with the saved wood dust. Apply second finish coat closing the windows
as you pass them. Next morning, vent and hand sand, damp rub, vac
twice, then apply third coat. Do at least 4 coats in order to have a
good strong finish. I did 14 coats on mine, tinting in different
rooms to set an atmosphere. Transparent pink in bdrms for warmth.
Blotched silver in study. Clear in lvrnm. Red in dngrm. All floors
needed was a light dusting. They still looked like glass 20 yrs later.