Svenska Spels over/under odds exclude OT. Bet365 does a poor job conveying their rules around wether their over/under odds include or exlude OT but if you compare the other odds for the same match they are very similar between svenska spel and bet365 which makes me think bet365 over/unders include OT.
If this is the case you can loose both bets.
example: Bet A: 2.5 under bet365 including OT
Bet B: 2.5 over svenska spel excluding OT
the game goes into overtime with 2 goals, you have now lost bet B. In OT a 3rd goal is scored. you’ve now lost bet A.
Always check overtime rules