@rruben02 - traditional boxers are probably your worst choice for underpants with a pad. I’m fairly sure the instructions on the various pads for sale even say somewhere on there that they don’t work with traditional boxers.

I wear boxer-briefs, and those work fairly well for everyday wear with a pad or shield. I do find snug provides more protection, but at a cost of comfort. Unfortunately, it’s a trade-off, AFAIC.