I’m not sure this is a big enough problem to worry about, and as James wrote back in 2023 fiddling with it may cause more issues when run against historical data.
This is a quirk in the query we use here on meta but not something most people will notice or care about. It came up now for you @NateDhaliwal because of the backfilling.
Like Moin, my tester and senior tester badges show the same date. In my case it’s Aug 9, 2014. Weirdly, the earliest bug reporter badge I got is a year after that, Feb 18, 2015. 
Maybe that first bug topic I reported got deleted.