you're stronger than me so take my comments with a grain of salt.
On rep 4 you lost your tightness, you can see you starting trying to press the barbell with your arms and your elbows were flailing all over the place - I guess this could mean it is just too heavy for you or the barbell got forward of mid foot (or both?), no harm done we've all been there.
But I got deja vu and had to cringe on the failed rep and can only hope you didn't break your shit.
Your safety 'pins' (or the equivalent you are using because you don't have a proper rack) are way too low for you. You are really lucky you didn't get injured on those last 6-12 inches of dropping. The lesson I learned the hard way in 2019 with about 365 lbs. ironically: safety pins should be just below (as close as you possibly can get it) to the bottom of your squat.
Not sure how much you paid that spotter but you should ask for your money back - actually, from there I don't really know how he can help except maybe to soften your fall if you should happen to fall backwards (in which case he is fucked).
Your second video looked much better to me, personally, but I am sure the more experienced guys will have some useful tips for you.
Hang in there! You are quite strong!