It does sound familiar.
If you have determined that it is not a power issue, then it may be same problem we had when we took delivery of our fifth wheel. The linear actuator under the bed died. Fortunately, ours died in the tilted configuration so the bed, although now unusable, was in a retracted slide.
We had an upcoming camping reservation so I temporarily fixed it this way until Heartland could send me a replacement:
1] remove the mattress in order to access the plywood sheeting under it.
2] remove the screws on the head plywood sheet above the hinge-line and the one below the hinge-line and place the plywood sheets aside in order to access the linear actuator that tilts the bed.
3] pull the cotter pins at the top and bottom of the actuator to remove it.
4] you can now replace the plywood sheets then mattress and tilt the bed manually as you retract the bedroom slide.
: With the linear actuator removed, there will be no resistance when retracted and it will try to extend again (quite forcibly). So take care to place something at the end of the bed to cushion it against the dresser or whatever when the slide is retracted.
This is a picture of the linear actuator that died under our bed:
View attachment 65022
I hope this helps!