Hi Mario-Barba,
It's common that you have boxes that don't match. Typically speaking, Box 14 of your T4 should equal Box A + Box J from your RL-1. Sometimes, there are additional items in Box L for the RL-1 that are included in Box A but not on Box 14 of the T4.
I would also advise to speak with your employer as they would be in the best position to explain any differences between both slips in case other boxes don't match up.