When we bought our 2014 KZ Spree, we had to replace the regulator because it wasn't working properly. Installed a Marshall and all has been fine after that. Doesn't sound like that's it tho.
Your Connect 303RL has the fridge in the slide. Same as ours. There is a flexible propane hose under the slide that moves as the slide goes in/out. It's not hidden and should be able to clearly see it and may be able to see if there's visible damage. The 12 volt DC power into the fridge and slide lights is part of the flex track thingy and maybe that is also damaged??