You might try lubing up the assembly. After the penetrating oil has had time to work into the latch, apply steady pressure to the release cable.
Have not had a problem with our battery tray latch, as it is not cable activated. However, the front nose panel that releases to access the generator uses a similar mechanism and requires regular lubrication.
Travel Safe and with a Smile! Pat
2020 Tiffin Breeze 33BR
2022 Cherokee Trailhawk toad