I have pasted below your sessions. You have something up with the scales or you’ve got a chassis that is showing issues. Is the wheel centered? Seat bound up? Spindles at same ride height? Same ride height across axle? As many have mentioned, make sure you have air the same all around and scale must be level.
What scales are you using? High end as in intercomp, longacre or possibly bathroom or postal scales?
If you have a digital angle finder that is the best way to get level if you don’t have a high dollar level. Check out menards, lowes etc for one. Can place it on top of your level. Once scales are level you can also double check rear axle by placing on axle.
Session 1 – No weight LR is 84#
Session 2 – Proposed weight LR is 92#
Session 3 – Weight actually placed LR is 84#
If you truly placed 10# near where session 2 shows, that number should not be equal to session 1 with zero weight in the kart. I would like to assume you will see 7-8+ lbs min on the corner. Your RR went up 5# also. In theory with the weight added to LR and LF that RR number would have moved lower by a bit.
Just my .02. Hopefully we can all work to get you squared away.