Ok After further looking into this.
I have switched modems now and that means I have changed everything except the underlying software. I have even changed ADSL providers to see if that is the issue.
When disconnecting from a remote PPTP server there are issues that have presented themselves on totally different modems. These issues are not apparent when using PPPoe within the pfsense box. Both modems reboot themselves when disconnecting. The connections hang and then about 3 minutes later both connections work again.
I have used different hardware for everything and it seems like a software issue.
I would really appreciate some kind of help here. I know the devs are busy but this seems like a pretty important issue not just for me but for pfsense.