AX 2012 - Latest code not picked up (Batch X++)

I had a batch class that generated Excel reports, and it was running fine.

We did some modifications to it and it runs fine(as per the modification) when we run as ad-hoc(without using the Batch tab from the parameter selection ).
But when the batch job is run it picks up the old code and not the latest version.
We deleted the previous batch jobs and created new ones thinking that it might pick now… but no luck.
We ran a IL and thought it might pick now… but no luck.

And now somebody suggested, to restart AOS and stuff… I am not sure I want to try that If I am not so sure that this will fix the issue.

I have the dev. knowledge, but I am in no way a technical expert. Any suggestions?