I haven't been watering much.
I'm not sure what the problem is.
Your statement above is what concerns me. Small amounts of water is never a good idea. IMO, when in veg and you plan to up-pot, you either you water completely, or you don't water at all.
Not knowing your soil, that's the only advice I can think of right now.
What size are the pots you have them in? They don't appear to be ready for a transplant, but IDK what size pots you are using.