In my view, if the motor was on the way out (lifting the roof slowly or not at all, I think you would smell it dying or it would smoke like most all DC motors do just before they expire.
Candidly, I don't know didily squat about your unit but I too have an electric lift on my unit (see signature) and I do know that on your unit and mine, the motor is not direct coupled to the lift mechanism but runs through a gear train that reduces the motor rpm and increases the lift power.
Having said that, I would inspect the gearbox / gear train and see if there is sufficient lube in the gear case or on the gears (grease).
Your unit is a 2005 which means it's not a new unit and I bet the origonal owner never serviced (greased) the gears or gearbox. A 2005 pop up trailer is considered ancient today.
You can get chassis grease in tubes (grease gun) or in plastic tubs at any auto store. Might be grease time.
Just a thought.
Conversely, if it's a hydraulic lift, all that may be the issue is, it's low on fluid and AW hydraulic fluid is nothing more than motor oil with an anti foaming additive, again available at any auto parts store as well as Tractor Supply in quarts, gallons and 5 gallon pails.
I suspect, lack of lubrication and age is your issues.