This is just an observation, but I see most of your units are set to Minimize Losses. This can cause them to only make superficial attacks, and makes it easier to force the unit to retreat on defense. Most of your Tobruk garrison is set to 1 Dot, which makes it easier to force a retreat.
8.2.10. Unit Loss Tolerance Orders
Unit combat actions depend on the unit’s Orders
Emphasis, which is a relative gauge of casualty
§§ Ignore Losses – Units will attempt to either
seize or defend locations in combat, regardless of
§§ Limit Losses – Units take losses into
consideration in combat; they will either
break off attacks or retreat from a defense, if
necessary, to preserve themselves.
§§ Minimize Losses – Units will make only the
most superficial of efforts in combat. If the
enemy is very weak, they will press their attack
or defense. If the enemy is strong enough to
inflict significant losses, the unit will break off