ios mail sender have additional unknown senders

I am using an Iphone 8. I have Gmail as my only mail in my IOS mail program. My IOS contacts are synched to my Gmail Contacts. I have combed all the contacts for duplicates and would say i have a good data set.

I've notice that when some people send me an email, when i view it in my IOS email it adds additional senders names (with an Ampersand in between them) that have absolutely nothing to do with the original email, the additional senders have no connection that i'm aware of to the actual sender (listed first in the "from" line"). When i look at these email in Outlook on my PC in only see on sender, the secondary addresses i see in IOS mail are not visible at all.

my ask is can anyone tell me where IOS email is pulling the names to the right of the Ampersand from?