I have had the same problem in the past, but I found a solution.  This occurred every time I made some change to my forum options.

I found that I have to uncheck and recheck the boxes of all the forums I am interested in and wish to be notified about when new threads are posted.  I also clear my cache if I change a quolte.  When I do this, the ebots continue or start arriving in my mail from that date forward.

I've tested this on three different occasions and found the results consistent.

Give it a try and see if it works for you.

Suzanne

“Music is harmony, harmony is perfection, perfection is our dream, and our dream is heaven”
Henri Frederic Amiel