Do you think this could have something to do with it?
I don't think so!My guess only:
your family changed their surname to avoid beeing tortured and jailed (somewhere in Siberia) by the Communist Polish Government wholy formed and controlled by the Soviet Russia (until 1989).
They were after anyone fighting in the Polish Army... formed abroad Poland
- just to remind you the Soviet Russia attacked Poland in 1939 soon after the Germans.
Your grandfather was, as you mentioned in the 1st Polish Armoured Division
formed in the West Europe.
Here is the history about the Polish Military Forces in the West , which were formed to fight Nazis and their allies.
Here is the story about your grandfather's Army:
There is a good movie (Polish) about one Polish officer returning after the war to Poland (from England) and how he was treated. The movie title is "Kuchnia Polska" (1993)
If your grandfather didn't protect himself (by changing the surname) I'm sure his life would become unbearable.
They were after anyone fighting in the Polish Army... formed abroad Poland - just to remind you the Soviet Russia attacked Poland in 1939 soon after the Germans.
Want to add, that they were after any remaining relatives of these soldiers as well. If exposed as a relative they were treated as these soldiers - as a traitors to communism.
After the interrogation and torture they were usually sending the people to the Siberia region or other part of USSR-Russia for a long term inprisonment with hard labour.
That's why your relatives were so scared and didn't want to talk about it, especially to children.