Rightly, or wrongly, it’s working as designed.
if you don’t work manual mode a lot, you can easily hit the rev limiter coming off an exit or comically fast taking off and holding first more than a second.
I took one of the runs in Raptor Assault’s pea gravel cone course in sport mode / 4a thinking it might buy me a little forgiveness on the 2nd turn. It didn’t.
Once stability control took over it cut all power for what seemed like the better part of a second, but I’m sure was faster in actual time.
OP is right, once you hit the rev limiter, the paddlers or gear buttons are disabled until you are no longer cutting power by the rev limiter, then you can upshift. I don’t know if this is the rev limiter strategy, or stability control but I’ve observed it too.
@goblues38 &
@Booth9999 are also correct. You would need a cr@p ton of practice to get reliable and better than the automatic shifts in sport mode at 3/4 throttle or more. it’s best to just short shift first and plan your shifting so aren’t in some awkward position when you need to down/upshift.