AudiA53LQ

Its a 7 speed gearbox*

Hello , so I just purchased a use Audi A5 (2017 B9 3.0L Quattro 218PS auto version I think its an 8 speed gearbox.(Diesel) it has 127000 miles ... It's supposed to have a 3 month warranty. First few days of having it I decided to get it stage 1 mapped and gearbox tuned as well. Driving hard prior to remap was fine I never noticed anything. The remap has taken it from 218 to about 290 ish. But the day I got the remap done I went to overtake a car I floored it for kickdown and I felt a hard thud like it was knocked out of gear (clutch slipping?) and car went straight into limp mode , "gearbox malfunction no reverse gear" on dash. I pulled in and turned it on and off and it went back to normal , shifts all still seem smooth , no noises or anything, only happens when you floor it/drive harsh acceleration. I tried it once more later , about 70-80% throttle no kick down and sure enough same thing happens again about 3-4k rpm. Here is what obd11 says I'll post it below. Is the extra torque from the remap highlighting a slipping clutch/bad clutch? says something like "excessive clutch B slippage" P081E00. No other fault codes that I can see other than one for A/C. 02 Transmission System description: 0CL 30TDI RdW Software number: 8W0927155L Software version: 0004 Hardware number: 0CJ927156 Hardware version: H03 Serial number: 0000000143 ODX name: EV_TCMDL382021 ODX version: 002024 Long coding: 000001 Trouble codes: P081E00 - Excessive Clutch "B" Slippage Intermittent