This quality control issue was not the total problem and exists in both 2020 & 2021 model years
Turns out another screw up as to welds to seams in the floor did not get done correctly so instead of the correct fix BGP put a patch over the seams
& also did not install a hose on the coupler that goes to the fitting the TSB was all about
So water from using the A/C (& more A/C is used, then more water draining) runs down that coupler to under side of passenger floor
and is blown rearward to where the patch and seam is, water runs under the patch edge, through the seam and back up onto top of the passenger floor
and soaks carpet & if not caught will grow mold

If not wanting some dealer to screw around with your C8 or joyride it :-)
take off under tray and below floor on passenger side you will see (as below ) that drain coupler, patch and seams
Use like a 15 mm OD hose that fits well into that coupler, hose long enough to carry water out to ground
Use a good weather sealer to assure the seam and patch (if installed)