See my post linked below - Monzo told me in September last year that the issue was with World Pay rather than Tesco or Monzo. They told me at the time their payments engineers were working with World Pay to get it fixed. This was in relation to when a Tesco transaction duplicates later that day/next day when the payment settles, leaving the original transaction still pending.
It’s definitely not an issue I’d noticed with my previous bank, although they didn’t show pending transactions a lot of the time, and I was not nearly as on top of monitoring my financial stuff in those days, so I can’t say that it definitely wasn’t happening.