Synchronization lost with several VST Instruments

I’m working on a project exclusively written on Guitar Pro. The drum part was exported as Midi in Cubase and the bass/ guitar parts are played from gpx files (Guitar Pro 6) with the VST AmpleSound (AME2, AGG2 and AMR2). The partition lasts 42 minutes and 57 seconds and around 38 minutes, at a precise passage there is desynchronization of AGG2 and AMR2. There are no errors on the partitions I’ve already checked. The problem is either software or hardware, but as a novice, I don’t know where to look. The VST instruments used are: Superior Drummer 3 and the 3 guitars mentioned above. For more hardware and software informations, please check my signature

Thank you by advance for any help