Hi there,
Just a hunch , but do you “Flush the serial” before sleep…LOL 
I think on ESP it’s like mom saying brush your teeth before bed. ?
also the EXT0 and EXT1 is another way. There is a thread of course I can’t find it now… but it has “ESP Sleep EXT0” info. Try that search term …
HTH
GL 
PJ 
It’s something pesky or syntax and the matter it wakes immediately back up is the indicator. 
try the flush.