Ok Hun I'm going to tell you what I would do - and I honestly think it will work but you have to stick to it for longer than a week.
Your nap is creeping backwards again, it's causing more EW and an UT/OT loop IMO. He's over 18 mths so I think a 1.5 hr nap is ok with a shorter day, it's not ideal no, but it's not terrible either.
So I would do this for a week....
If WU is before 6.30 keep in cot, otherwise get him up.
WU 6.30
Nap 12.30-2.30 if he sleeps longer wake him up...2 hr nap is restorative.
BT 7 (or as close to it as you can make) - if the nap is only 1.5 you can pull BT forward if you need to.
If WU is later then move the day with it - nap goes later, BT goes later. Or if you want an EBT or 12 hr day you may need to cap the nap yourself at 1hr30/45
The crankiness could be a ton of things. t is a crank ATM developmentally.
go out for the morning then give him a snack or lunch before cranky time hits. Plonk him down for some wiggles and a cuddle if he's struggling. Or read some books
HTH