Sleep is not a linear development. It often gets worse for no other reason than it being a developmental change in the baby. So it is important to be able to be flexible to change things or the way you do things according to how the baby changes.
It seems that the developmental leaps your LO made has affected his/her sleep.
I can only give advise on my experiences. My DD's (8 months) ability to settle to sleep went to pot when she learnt to stand and climb recently (not long after learning to crawl). One day she was fine in her bedside cot, seeping bag and dummy - fed or not if she was tired she just went to sleep with her dummy. Then within 2 days she was climbing the cot sides, I had to lower the base of the cot and put the side back on. She would do circuits in the cot, rock on all fours, crawl, roll, climb, stand. Anything but lie still and sleep.
We solved this by bringing back the swaddle - which DD loved in the first 12 weeks of her life but aside from brief returns when over-tired, the swaddle hasn't been used for ages. But you know what? She loves it. Used currently for night time and naps and as soon as her gets that tight, secure feeling all around her (just like being held and cuddled by Mummy), she is immediately still, calm, content and sleeps within minutes with her dummy.
I wonder if my DD is showing me that she will be the first of my four children who doesn't like a sleeping bag. Maybe she would prefer to be tucked in tight with a blanket. These children do have personal preferences which will show though as they get older.
This sort of thing (swaddle or tucked in blanket) may or may not help you. But the point is trying new things to figure out and solve the problem. This can of investigating and trying out new ways and new things is much better and more effective than the arbitrary sleep training that you have been trying.
Your sleep training methods suggest that nothing needs to change and that you can just 'make' or 'teach' baby to fit in with the way you want him/her to sleep. I am suggesting that if you try changing things and doing new things, rather than assuming sleep development is linear so needs no changes, may work better.