There's a lot of us Omnipod users with this issue and some oddly who don’t, I do most of the time but not always, no logic to it at all. To combat it I leave the old one on for a few hours but also do a temp basal of 40% for 2 hours if it’s on an underused area or really un fatty place such as high stomach and do a 70% for 3 hours if on my thighs or glutes. Mostly this works and if not I do a small basal. It’s not a tried and tested method and my insulin rates are low which might be a reason why the new pod takes a while to bed in. Good luck, it’s a pain!