I have an XDm 3.8 that won’t go into battery. It’s an intermittent problem. I never know when it’s going to happen. It ejects the empty brass, picks up the next cartridge and then the slide stops just before going into full battery. The only way to get the slide working again is to push the corner of the slide on something hard and put all my weight on the grip. Sometimes I’ve had to whack the back of the grip to get the unforced shell to eject and release the slide.

I want to sell this as I was going to use this as a ccw. Do I sell it with full disclosure? Take it to a gunsmith and try to get it fixed before I sell it? Send it back to SA and hope it gets fixed sometime this century? I don’t want to sell someone a lemon but I want to sell it with minimal hassle. Thoughts or opinion? Thanks.

Send it to springfield and get it fixed

Or, sell it with full disclosure.  Just don't expect full retail value if you do this.

Has it been cleaned and lubed properly?

Send it to Springfield. I bet the chamber is cut short. Easy fix.

So what happened?
You didn't mention the ammo used when it happened, could be that.
I've seen it happen on a compact one, advised shooter to smack the back of the slide with heel of support hand, it chambered and then fired when the trigger was pulled.

How worn out is the recoil spring? I never had this problem with my xdms

I had a similar problem with a S&W a wile back, the problem I had was the recoil spring was so worn out that the slide didn't want to go back into battery. So I bought a replacement spring from wolf springs (check em out) and the gun hasn't malfunctioned once, and just for the record, I've rad some pretty cheap and dirty ammo in it.

Try racking the slide and if it feels very light I would try changing out the spring, make sure it's cleaned and lubricated well and maybe consider using different ammo, if you were using cheap Russian steel case that maybe the reason why it's malfunctioning.

It not of that works send it back to Springfield and let them take care of it, they have good customer service.

Hope this helps.