My son-in-law has a Salem trailer. The 3"pipe from toilet to tank looks like it goes to about 2" from bottom on tank. Therefore the toilet solids will not flow out in the tank. I think the pipe needs ...
2" from the BOTTOM is definitely not right. I can't believe anyone would think that it is normal. If it really is like that, you are going to have to fix it. Is this a new trailer? That would be a warranty item. If an old trailer, pipe might have slid down. Doubtful that anyone would live with it like that for long term ownership, but then some people never use their toilet, so anything is possible.