Wetting the bed after being dry for 6 months

[Elemis]

Ds is 3.8. Has been dry at night for 6 months, not a single accident.
He has just wet the bed twice in the last 2 weeks.
Any ideas why?
He can hold in the biggest wee ever, and doesn't even have to go immediately as he gets up.
really not sure why this is happening.

he's also having real trouble settling to go to sleep, really wriggly and just can't settle, so a few major tantrums. not sure if the two are related

Wet the bed again last night.
It was this morning, he said he was fast asleep, so how is he supposed to wake up?!

My six year ol still very occasionally wets the bed. Usually when she is worried about something. Is he a worrier?

I can't think of anything he could be worried about. he's not really the worrying type.

but i'm worried now, looking at all the reasons, it seems to be when they have something on their mind.