I quickly updated the TFT using the latest firmware, and did few tests.
Look like the problem is…
GONE!
I will need to test some more as it was rush-rush, but 4 boots equals 4 times normal operating speed during travel. So atm it looks like a rare bug in the TFT firmware that has been solved.
did you use the latest forked for mpcnc or from the Bigtreetch original? link would be nice 
Hello, sure I downloaded this one:
WOW- this has become quite the thread. I would like to know- Why have I not seen this issue on my rig using running Marlin_V1CNC_SkrPro_Dual_2209_2.0.7.2_510 with the BIGTREE_TFT35_V3.0_E3.26.x.bin? Is this ‘bug’ in my firmware as well? Just trying to ensure I understand what we have learned here. Thanks.
OLIVER- Glad you got it solved!
I wish I could tell you the exact reason why this is triggered on only some builds.
What I can say for sure is that Marlin mode had no issues.
TFT mode did. After TFT update to @jeffeb3 newest version on GitHub it looks like it is gone.
Maybe it has something to do with the SKR Pro version (I have 1.2), or combo with the display,
Maybe it has something to do with travel direction: @Kip travels same direction as me after boot,
…
Now, since you originally had this issue, I might advice you to update to the newest version too?
To see if it makes any difference for you.
hmmm… I have the SKR Pro 1.2 and the BIG Tree BTT TFT35-E3 V3.0 with the firmwares above… no issues since… I have a buddy with the exact same build parts and F/W- no issues there either… Believe I will hold tight unless I ever see the issue again- If I can’t tell it’s broken, leave it be!
Yes! that´s what they say: don’t fix what isn’t broken!
I’ve been told that the engineer’s mantra is "If it ain’t broke, fix it 'til it is.
My guess is that in Marlin mode, during a print, the knob changes the feedrate. When the touch screen is jogging, it is sending G1 commands to move the machine. Marlin thinks this is a job/print.
The bug is that the screen is sending Marlin the encoder pulses and sending gcode at the same time.
Marlin sees the gcode coming and the knob turning, so it assumes the user is trying to print and adjust the feedrate.