For example when I was playing Bedwars I couldn't change my Main hand slot whilst iw was shifting when building the bridge. To make sure this wasn't an issue with Hypixels end I tried it in Single player and I experienced the same issue. When I play on the Windows version of Minecraft Java I don't experience this problem

What I expected to happen was...:

I should have just been able to use My mouse wheel to change the item slot whilst shifting

What actually happened was...:

When I tried to Change main hand item slot with mouse wheel the slot selected didn't change
Steps to Reproduce:
1. Hold Shift
2. Try to move Main hand slot with mouse wheel
3. And it doesn't move