For starters, you can check out this FAQ that covers saddle issues specifically, but can cross over into other fit issues
Lifting the front axle higher than the rear is something I like and recommend. Fine tuning that to preference can sometimes help with hand, arm and shoulder issues but it’s not a cure-all.
As Landis mentions, differences in trainer flywheels and the related forces at the pedals sure could be at play here. Some trainers to a better job of replicating that feel vs others. What trainer are you using?
In addition to the trainer, consider your cadence between inside and outside. Is it similar or different?
And as covered in the Saddle FAQ, I will separately mention the consideration of adding some ‘motion’ to your setup. You can start with simple foam mats and the like to see if some amount of movement (vs the typical rigid trainer) is beneficial or not. I can go into more detail if you are interested.