Hello,  been using start V1.55 for a while now specifically to have my taskbar and start menu top aligned to my screen on Widows 11. 

PROBLEM STATEMENT: Since May 13th (ominous) I can align my taskbar top of the screen, but I no longer get thumbnail previews of apps like chrome making navigating multiple tabs of Chrome impossible. 

ALTERNATIVE BEHAVIOUR: If the task bar is bottom aligned, everything works fine because the preview generates upwards - i suspect the preview doesn't generate downwards when the taskbar is top aligned

Below you can see bottom-aligned works:

Here is the taskbar aligned top and mouse hovering on Chrome -  note there are no thumbnails - marked in blue and red

Start 11 has  enhanced features switched on:

Settings are for top-aligned and HIDE TASKBAR is not active on my system: 

System Details: last Windows update was May 13th - rolled back, and this issue persisted