'Difficult' to click / select in-game world tiles

Hi,

I am trying to play the game across a Windows Laptop (Work), and at home Mac Mini, Apple Silicon. 

At work things work okay, but the laptop is underpowered, graphically.

The Mac works potentially splendidly, with my ultra-wild monitor...except that I cannot click/interact consistently with the tiles / objects in the world. Occasionally I can click / select / drag to select a tile to tiles for example, to be cleared, but most of the time I cannot - so it make selecting tiles for an action, picking up creatures, or casting spells etc a 'fail' 95% of the time. 

The UI works fine.

HELP!

Damian