Thx for all the suggestions; esp Macnaz for putting a lot of efforts. When I opened TT (Winows PC Prem) there was an update waiting for me.
After updating I was able to check Box "C"(at top of 2210 Form, above Part I): "Checked"; ("Check to have the IRS figure the penalty and send a bill if penalty due").
Today my return got accepted. I didn't have to play any games with Form 2210.
I verified using "Step by step" that no penalty is due.
