Hello @Plauflaulla67
I already received an answer from the Roaming Team:
"In order to be able to bill calls in real time and in compliance with the new federal roaming rules, we have implemented Home Routing."
That means that the behaviour you described is correct: if international calls blocking set is activated, you will not be able to reach local or third country numbers once you are abroad either. Only calls to Switzerland are possible, which I admit is a bit awkward.
However, the description of the My Swisscom barring set will be adapted at the end of July.
I am sorry I was not able to give you this information in the first place.
Please let me know by sending me a private message your mobile number and the date on which you called your mom. I would be glad to check if that call has been charged and credit you the amount.
Have a nice afternoon