I get those every year, since apparently the employee at the tax office can’t see where the realized P/L is on the report of IBKR - it always takes a 5’ call to tell them that I didn’t sell anything, hence it’s 0…
Even more funny is that on a comment from my side as to why they (their software) doesn’t calculate that based on entered sales/purchases the answer was “that’s not our job, but you have to give us a report from your bank”… I felt a bit perplex, but the tax office can be very competent and very stupid at the same time.