I find a "dead zone" directly under the icons between the "Advancements" and "deploy" where you cannot click on the screen or units.
As if there is a "ghost" image of a unit details box - it corresponds exactly with the unit details box.

<t> Situation<br/>
France fell with Axis occupation of all of French North Africa<br/>
Only Syria and part of France were Vichy<br/>
<br/>
Spring 1942<br/>
US/UK invade Morocco and begin retaking north Africa<br/>
<br/>
May 1942 <br/>
Axis declares war on USSR and invades USSR<br ...

Move naval unit using one action point to A (one action point left).
Select the same unit again and move to B (now zero action points).
Hit UNDO and unit goes back to A with TWO action points restored.

Effectively, infinite movement rte for naval units!

When you join a naval unit in port to a unit that has already moved, for instance, by loading a land unit onto transports, then the new unit cannot move.

It appears the new unit gets the "already moved" flag.

Attached is the log file

Attached is the DXDIAG output

<t> Playing a 1939 game as Axis vs AI and reached 1943 having taken all the USSR cities and resources. There are no USSR units left on the map.<br/>
<br/>
On finishing the turn, the AI starts the Allied turn with the USSR, deploys partisans and then hangs up indefinitely.<br/>
<br/>
Map still ...