Stuck on wallpaper

https://happilyeverafteretc.com/how-to-remove-wallpaper-like-a-champ/

Have you used a wallpaper scorer and DIF? I have found using these together to work on every application I've tackled. Only mix enough DIF for a smallish area at a time (maybe ceiling to floor and 6' across). Let it sit the necessary length of time. Use HOT water to mix the DIF!!!

Vinegar and water mix in a spray bottle.Spray the paper and let it set about ten minutes then try peeling it off.

Did you rent a steamer and scoring tool? That is what I use, and yes it can be challenging. I score the wall till my arms want to fall off. The more steam that gets into the tiny holes the easier to remove.

https://www.lowes.com/projects/paint-stain-and-wallpaper/remove-old-wallpaper/project

My son's bedroom wallpaper was about 15 years old when I removed it. I took a spray bottle and filled it with hot water. Then I sprayed a 12" section from ceiling to floor. Let this soak in and sit for 5-10 minutes. Then take a putty knife and scrap the damp wall paper. I found that if there was a seam, if I sprayed the seam and to one side of it, I could slowly take an entire section down. It worked for me, I hope it does for you.

I've heard fabric softener works when sprayed on . have you tried steaming it off?

Depending what you have tried the wallpaper may have been put on directly on the drywall without primer or sizing. It will more likely not come off without damage to the walls. I would just sand/feather any rough edges smooth and use a stain blocking primer over it. I have had to do this many times when people thought they were DIY's and couldn't do it themselves.

I too remove wallpaper for clients, and I use fabric softner in hot water in a washpan with a car sponge or use a garden sprayer or spray bottle, wear rubber gloves. Tape off the floor from baseboards down with plastic tarps, and I put a thick layer of newspaper to absorb any runoff and keep it from getting slippery. Score the paper with the scoring tool so it can penetrate.

I saturate the paper with the sponge holding the wash pan underneath to catch most of the runoff, work in 4 foot sections, move on and saturate next section and then go back to first section and rewet again. etc. wait at least 20 mins before you try to scrape. If its not giving, re-wet again using a fresh batch of hot water and fabric softner.

It will probably tear up the drywall cause someone didn't finish the wall before putting it up and I've also encounter people using glues other than wallpaper paste. You can skim coat with joint compound when your done. https://www.youtube.com/watch?v=cs3I4z0RhCM&t=34s I use both the 12" drywall taping knife and a 6" one.

Sorry it didn't work for you!