I'm playing Mechwarrior 1989 on a 386 computer with an intelligent mode MPU-401 card I bought here and areal MT-32 old version.

The problem I'm experiencing is that when I turn the Turbo button off the game freezes after each battle.
If I remove the MIDI card from the computer and play with Turbo off the game does not freeze and it also does not freeze with MIDI card inserted and Turbo on.

It's a known problem with this game in Dosbox that you have to set MPU-401 mode to UART not Intelligent or the game will freeze after battles.

Is there a connection between hardware speed (turbo on/off) and MPU401 mode (intelligent/uart) or this is a mere coincidence and the root of the problem is impossible to decipher?