I just have had a look into datasheet of TB62706 and, indeed, it is reported, that misstriggering can occur due to inductance and impedance on ground.

So, a bit signal processing will be helpful!

Connect the /ENABLE, CLOCK, /LATCH, and SERIAL-IN lines not directly to the microcontroller, but to the output of a 74HC14 Schmitt-Trigger sitting very close to the TB62706 and sharing the same Vcc and ground potential.

Now, put a RC-low pass filter at the input of each 74HC14 Schmitt-Trigger. Choose a time constant, that does successfully filter out narrow glitches on ground, which appears as ground noise between the microcontroller's ground and the TB6207s' grounds and is seen at the inputs of RC-filters. If I understood you correctly, you have ten minutes to load all the TB6207? This should allow you to choose big RC time constant, filtering out any ground noise!

I would feed the TB6207 individually, not all in a row, because of this serial-out to serial-in connections. Or, clock the last of these TB6207s in a row first.

Kai Klaas