Hi @phil_1 , hi @creative explorer
Thanks for posting your queries and hiccups.
Reading down the comments, I see issues working with Hand tools and key shortcuts in Modern viewer. Please follow the below instructions to have a seamless Acrobat experience(without switching back to Classic view):
1. Hand tool can be accessed from Quick toolbar, where Select tool option is displayed. Hand tool is available as an option.

2. For using single key accelerator i.e. H, make sure below preference is turned On:
General > Use Single Key accelerators to access tools
P.s. works for both Win and Mac (requires app restart)

3. Holding Spacebar brings the Hand tool temporarily.
Let us know if this works for you!
Thanks,
Team Adobe.