DM 3200: using user with protools, using a plugin (Xpander2)

[M Eubie]

DM 3200 mixer. Recently, I was working on a production in protools, using a plugin (Xpander2). After arming the track, using my yamaha keyboard to play in the part, after a stopped playing (with the track still armed), got a low frequency sound after I stop playing. I tried to resolve by calling and talking with with tech from Sweetwater. I run something diagnostics, but was unfamiliar with the Tascam board. I tried troubleshooting it myself after reading somes steps online . So (in protools), I went into the Setup menus to "peripherals" MIDI Controllers (#1 and #2) to checked port 5 and 6 (From/To) were chosen. Then, I (followed instructions) went into MIDI input devices and unchecked 5 and 6, only to discovery that unchecking 6 disonnected autiomation on the DM 3200. So I recheck the boxes and returned to the MIDI Controller and chose "none" tp unassign (one at a time) port 5 and 6 (From/To). As I tried each of these troubleshootings options, I test pro tools to see if the problem stop, which did when unssigned port 6 (From/To), but channel 9-16 automation was disable. After using the Sweetwater and trying to toubleshoot the problem myself, is there/are there other things I can do to resolve the problem? I (anxiously) look forward to feedback and insight. Thx.