I bought a small batch of inexpensive vinyl peel and stick floor tile
for a 3'x15' basement closet. This closet doesn't get a lot of use,
so wearability is really not an issue (that's why I bought the cheap
tiles). I simply wanted to cover the floor. If I recall correctly,
this floor was painted with an oil-based floor paint about 15 years
ago. The paint is sound and appears to be adhering well (the paint
stayed on the floor when I picked up one of the tiles). The adhesive
on the tile doesn't appear to be lacking - in fact, in a few places,
it squeezed out from between the joints. I should also note that
drops of paint and poly from previous projects are difficult to remove
from this floor, so it doesn't appear to be an oil or wax problem. I
tried putting bricks on the tiles, hoping that ensuring contact
between the adhesive and the floor would help, but, after clamping it
overnight, there was no difference.

What can I use to stick these tiles to the floor?