I've tried all of those things, I don't think it's a windows SMB issue since it worked before the router change.
I also enabled the no-df option which didn't make a difference either. It's just SMB as far as I can tell though, other protocols work fine.
Edit:
And it does work fine locally, just not over the ipsec vpn…
Edit 2:
face f*%king palm.... windows firewall. Somehow it was turned on again on the problem computers. I don't know how it got re-enabled, when, or why it worked on my old vpn. But I don't care anymore, I've been tearing my hair out for 2 days with this.
Thanks for the help guys, guess it wasn't a pfsense issue. It was the only thing that changed on my network so I assumed it was.