Is LaunchBox borking up DOSBox?

[tycho]

I dunno, maybe I'm barking up the wrong tree here, but I'd been using DOSBox 0.74-3 for a long time, as well as DOSBox ECE that I use specifically for games that I use a modern gamepad with, and I never had any issues. I had been running it on a Windows 10 PC, with a GTX 1070 at 4K resolution, and all my games ran spectacularly. I had custom config files for many games, but I usually just picked from three config files for the most part. Most games I have use Sound Blaster emulation, but I have a Roland MT-32 emulator for games that support that. Everything ran fine from LaunchBox.

I recently swapped my 1070 for an RTX 3080, but I hadn't tested my DOS games because I had no reason to think anything would be affected. Today, after four months of using the new 3080, I booted up a DOS game and I found some hinky things. I have some games that I got from the exoDOS pack, and some of those have a sort of "pre-run" selection screen, where you choose what sound emulator or graphics mode to use for the game - this screen shows up garbled, and I cannot read the text. If I guess the correct settings and start the game, SB sound stutters terribly, and MT-32 sound slows down when loading graphics (transitions, animations, etc.). When I exit the game, the command line interface shows just fine.

Some further testing showed more irregular sound behavior: Launching Space Quest IV from LaunchBox, then choosing MT-32 music at the "pre-run" screen loads the game and the MT-32 emulation, but then I don't get SFX (Sound Blaster audio). But running DOSBox manually (via command line, not within LaunchBox) with the same .conf file, then starting SQIV via the same batch file and choosing the same audio options runs the game with both proper MT-32 music and SB audio. Both methods still give me stuttering audio.

Since I have not changed any settings or made any changes besides the video card, I'm assuming that is the issue, but maybe could be LaunchBox? Does anyone have any ideas for troubleshooting?

P.S.: ScummVM games - and all other emulators I use - still run perfectly in every way.