Try swaddling and preheating the surface of the cot/bassinet with an electric heating pad. Place a dirty shirt over it. Then remove it all right before putting baby down. Slowly put the baby in. The snugness, smell, and warmth will convince your baby you are still holding them while they fall into a deeper sleep. If that doesn’t work try different mattresses. My baby loved his stroller bassinet but wouldn’t stay asleep in his cot.
Same as Yaz here, still co/chest sleeping (albeit he wears the Owlet sock for peace of mind), but as this is our last I’m embracing it…and husband cosleeps with the toddler so there’s space in our king bed 😅 Everything is a phase and one day he won’t want to sleep nearby 🥲
We cosleep, I gave up with the next to me a long time ago but I need sleep and can't sleep in the day as I have a 3 year old. So I have him next to me in bed following the safe sleep guidelines. If I move away even to go the toilet etc he would wake up. In the day time he is pretty much always on me or in the baby carrier.
Mine is the same, proper Velcro baby and normally wakes within a few mins if I try to put him down in the moses basket during the day 😅 we co-sleep at night in my bed and he will do a 4ish hour stint at first and then it’s hit and miss, sometimes I can put him back down other times it takes several attempts. The first week I was having to chest co-sleep at night cos I couldn’t put him down at all. I do love the snuggles and I think this may be last child so trying to fully embrace it but it’s defo hard to do with a toddler as well!