PPTP MRRU and packet fragmentation

I’ve just recently starting experimenting with MLPPP over single link PPTP connections. I’ve noticed that large packets do not fragment properly and I’m wondering if it’s a problem with my config.

If I setup a regular PPTP connection with MRRU disabled and a 1460 byte MTU packets fragment properly. For example I can send and receive a 1700-byte ICMP echo request/reply.

When I setup MRRU to 1614 on both the client and server I can only send a 1610-byte ICMP echo request/reply. For some reason the packets are not fragmenting properly. Has anyone else noticed this behavior?

I’m gonna give this one bump then forward my question to support.