Its often stated that regardless of any POD that gives Germany advantages, the Allies will drop the ABomb on Berlin in August 1945 and win regardless.
But even if the Allies have an Abomb in 1945, could the practical employment (with Germany stronger) be too difficult due to:
a) If Germany controls occupied France still, Germany can retaliate on England, with poison gas, perhaps delivered by rocket.
b) Germany has an air defense (backed by jets firing rockets or whatever) by this time that makes delivering a bomb risky.
c) Germany retaliates against the population of an occupied country (savaging an occupied Paris or something).
d) Nazi leadership is off in Wolf's Lair or someplace and so an A-bomb hit isn't going to force a surrender quickly.
e) Fear of some unknown Nazi super-weapon that might be unleashed in retaliation.
(a POD could be General Wever lives, leads to butterflies where a more effective Luftwaffe allows Germany to cripple the Soviets to a stalemate by the end of 1942, a more effective Luftwaffe is also a factor in the Battle of Atlantic, so Germany still occupies France in August 1945, an Allied cross channel invasion is feared to be super costly)
So even if an Abomb exists and is ready, could the Allies not want to risk using it?