Replaced battery, still nothing

The phone was rarely powering on. Occasionally, it would show the Samsung Logo, but then back to black screen. I was able to get it to charge once and it said it was 100%, but then after attempting to get into safe mode i haven't seen the charging screen or indication since then. I ordered the battery and tool kit, took everything off according to the guide (removed the residue from the case too). Put the new battery new, closed everything back up (without using any of the adhesive because I wasn't confident in my repair) plugged in the charger and now… nothing. No lights, no charging indicator, nothing.

I don't know how to test the battery to check it, but I am wondering if it is actually the charging port that isn't working? Does that make sense? Is there something else you would suggest trying?