2005 chevy express starved for gas

I have an 05 chevy express 3500 and when shifting into reverse it acts like its starved for gas. Or when shifting from reverse to drive it sputters and acts the same.

its a 6.0 and has 230k on it.

It also has a bad transmission in it that I need to get replaced, torque converter is slipping. But its been like that for a while, almost a year, and this problem with the sputtering just started.

Have you checked for codes?
Have you checked anything at all on the vehicle? Fuel line pressure? Fuel pressure regulator? Ignition? Anything at all?
how’s the maintenance been? Kept up to date? Neglected?

Maintenance has been kept up. I havent checked anything concerning the fuel, I just found it odd that it would only act like this when going going into reverse, usually from drive. There are no codes, at least the check engine light has not come on.