Slightly confused about this. My currency has always been in Canadian dollars. I live in Canada. After the last update it has changed to British pounds.
I’m from the UK but haven’t lived there in 3 years. I vacationed there at Christmas but this only happened today, with the new update.
What were you looking to purchase? I just checked mine for the store gem purchases (I’m also a Canadian) and it appears to be the the same Canadian price as in the past.
I had this happened while I was predominantly using USD and after vacationed in Taiwan a few months ago, the currency for the stores changed to the local currency and after coming back to the US, did not change back.
I have a feeling the same thing may have happened to you. You may have had a game update while you were vacationing in UK and used their Wi-Fi to do it. To try to resolve this, try logging out of your Google Play Store / iOS store while connected to your home Wi-Fi, then re-log in (do it for Facebook too if you would like), see if that helps change your currency back to Canadian dollars in the Shops.