I’m not sure about my boss he blows hot then cold

[Eskima]

I have started back to work after a 15 yr break ( having my family).
I have found it tough picking up on all the IT stuff.
But I have sorted out a big technical problem in the laboratory.
But my boss 10yrs younger than me can blow very hot and cold.
I noticed at the Christmas he avoided me the only space let was next to me but he went and sat at a table on his own.
Last week he came in the lab, I thought he was going to speak walked straight past me. Then when a coworker came in he was all fussy with them.
I’m lucky there are a couple of people still working here from the old days but they are not in my department.
I really dpn’ Want to give up. But I not sure I can stand being ignored and not spoken to every single day.

Your first sentence says it all. You're back after 15 years and it will take time for this to become your new normal and get to understand the rhythm of how everyone works.

I think any new job can be tough for the first three months, and then it settles down. Give it a good three months with low expectations and then judge. Too soon to call just now.

Good luck

Sounds like you've returned to the same organisation where you were 15 yrs ago?

Did your boss interview you and selected you for the job, but now you're in post, he ignores you?

Have you tried talking generally with him in a one to one situation to find out about his change of attitude towards you since he recruited you? It sounds like something has happened to make him change, but you haven't been told what it is. You at least deserve to be told if there's something wrong with how you're working so you can fix it, and move on, as it doesn't sound sustainable.