To add - the debugging only goes slowly at the breakpoints. That is, the execution is fine up to the breakpoints. Once it hits the break point, then TC will be unresponsive / freeze for several minutes.
I won't step through it and it will start running a delay loop that is no where near the control.
The delay loop will be something like
Do Until Some Condition
If Some condition Then Exit Do
On the watch list the value for all watched variables is
"Evaluation timeout. The script engine is not responding."