So, taking out friendlies, including the Europa League, Southgate's England have only lost to 4 teams in 8 years, at 3 major tournaments.
Belgium, ranked No 1 in the World at the time, in the World Cup group stage, when we'd already qualified, knowing that a loss would give us an easier route to the final; and he rested a lot of players.
Croatia, a smaller nation but a team containing players with far more international caps, and nearly twice as many Champions League apperances, than the England squad, in the Semi of the same World Cup, where we were leading for most of the game, where we continued to create clear cut chances, to a team that threw everything at us. We lost in extra time.
Italy, on penalty's in the 2020 Euro final ... the same Italy that had already beaten two of the top three seeds earlier in the tournament; Belgium and Spain.
France, reigning World Cup holders and number one seeds, where they scored their first goal after fouling Saka, and Kane missed a penalty that would have made it 2-2 late in the 2nd half.
All of the other defeats in the 27 - 6 - 9 - 12 equation were friendlies (training matches) where club managers pull their players out for little or no reason, and tactics/formations are tested out.
For 6 years, before Southgate was appointed England Manager, England had slipped out of the top ten in the FIFA Rankings (16th when he took over), however, we've either been 4th or 5th in each full season since he's been in charge.