Hi,
When it goes into spin mode, the agitator turns like it's in full spin mode but the bowl turns slowly like normal - this usually causes the machine to clump the clothes together & go out of balance, tends to be more of a problem when doing small washes/minimal towel loads. Is it a controller issue or clutch problem?
Also have the overflow problem will see if caused by a blockage in the flow level tubing.
Agitator & bowl should turn together at the same speed. Your brake arm is not releasing to allow the clutch spring to engage & drive the bowl. Check the brake release solenoid is working.