MCT8329A: The motor runs for one second and then stops.

I was just browsing the forums and came across the following link:

https://e2echina.ti.com/support/machine-translation/mt-motor-drivers/f/mt-motor-drivers-forum/776409/faq-faq-mcx

I made the following adjustments:
1.ALIGN_TIME=B;
2.OL_ACC_A1=6;
3.OL_ACC_A2=5;
I increased some alignment time and turned up the open loop acceleration A1,A2, the symptoms didn't get better, then I turned A1,A2 down and it would spin for about two seconds then stop again, the fault is still as follows:
1.LOSS_OF_SYNC=1;
2.MTR_LCK=1.

Right! Also I can't quite wrap my head around the following formula. Suppose A1=1HZ,A2=0.5HZ, can you help me to make an example of the operation? What should be the exact SPEED(T)?

I would like to add some information.
My motor is 14 pole.
I use an oscilloscope to detect the FG output under the following conditions.
FG_SEL=1H;
fg_div_factor=7H;
The result is no waveform. However, when FG_SEL=0H, you will see the motor stop at about 7HZ.
This seems to establish that the motor is not in closed loop, right?

I think I should have found out where the problem is, no matter which mode I use to run the motor, the motor can't run at low speeds, my motor is running on regulated speeds with an operating range of 500-1500 RPM, and I can never run it stably below 750 RPM no matter how much I try to debug it, assuming that I set it to 1500 RPM directly, and then gradually drop it down to 750 RPM. Unable to synchronise fault, if I directly drive the motor to accelerate from stop to run at 750 RPM, then it will stop instantly just after the closed loop has intervened in the motor, and also report an unable to synchronise fault. But although I know that it is the low speed running condition that the closed loop can't run properly, but I have no way to solve this problem, please help me!