[04str]

Gear changes are handled by the TCM but it exchanges messages (across CAN) with the PCM (and in some cases PCM with ABS but not in the situation of this thread I expect).

Battery off resets only the PCM's learned values (there are many). They include fuel trims, and many checks (reflected in the status of each OBD monitor and any codes which may flag).

Now, early TCM/PCM software could learn then later drift i.e. learn badly over time. New software (they get called calibrations) was provided so it would be wise to find out if you have the latest for your specific car. (Normally via IDS/SDD.)

The TCM's learned values are known as adaptations (sometimes adaptions) and can be cleared using IDS/SDD.

Of course none of this works properly in case you have such as: low fluid, worn ZF valve(s), some perhaps minor engine issue which is causing the PCM to co-operate badly, etc.

 

[04str]

Fluid level ... is fine

I hope they checked it exactly as ZF require - failing to do so is sadly common.

I also hope they used the correct kind of fluid.