Welcome Peggy! I agree with DW. You are using too small a blade for stack cutting 1/4". I use a FD UR #3 for stack cutting 1/4" and for 3/8"to 1/2" thick single pieces. I will even use a #5 for 1/2" if it is hard wood. If you have intricate cuts in a thick wood, you can get by using a #1, but go slow, slow, slow. Have you tired pulling the blade back when you reach a corner and spin the wood 180 deg. and back into the corner with the smooth edge, then turning 90 deg to start cutting the other direction. This usually keeps the blade straight on the line.
Toneman