BW doesn’t condone leaving them to cry it out.
Could he have some day/night confusion? Make sure it’s quiet and dark at night, don’t engage him. By contrast day time have the curtains open, chat to him, show him stuff. His body should adjust after some time.
If you post your routine it will help the clever ladies here check if the problem is elsewhere
Something like this:
WU (wake up) 7am
E 50ml
S (sleep) 8am
WU 10am etc
Also take a look at the faqs - amount of day/night sleep appropriate for his age to see.
Don’t know how to paste that in lol