I had the Deduplication error show up a few days ago.
I went to the Facebook channel on Shopify and changed data sharing from Maximum to Conservative and marked the error as solved.
Now I'm seeing duplicate events reported on my Facebook ads reporting. 2 purchases are reported as 4 and so on.
I used the Event testing tool on Facebook and I can see events are duplicate because one of them has the Event ID and the other doesn't.
Have you encountered this issue before? And what did you do about it?
I'm experiencing the same issue since this morning. I've tried contacting Facebook and Shopify, no-one seems to know how to fix this. Shopify said to contact Facebook and Facebook said to contact Shopify.
Have you found a solution @Z_Jonah
I tried a different theme and the problem went away. So, in my case, the issue was from the theme.