Mine does the same slowing. Completely normal.
If you have the gear showing on your dash above your speedometer, you can actually see it drop a gear at the same time it jerks you slower.
I know I've read numerous nightmares about the NON-eTroque‘s tiny secondary battery going bad causing havoc leaving people stranded unexpectedly but has anyone read a single negative topic about the 48v eTorque? Apparently it’s been out since 2018 according to post #148.