ERR_CONNECTION_RESET MTU fix?

Hello all,

I am getting regular errors when updating a particular website we run for a client - both Wordpress and OpenCart result in database corruptions to the page, item or menu which was being updated at the time. It happens in Firefox, Chrome, Safari etc etc. on any Mac connected via our work network - ethernet, BT Fibre Optic. It seems to only be an issue on our work network. I haven't yet reproduced this error from anywhere else. It also seems to only happen on this particular website, others have yet to show this error.

I have done lots and lots of research and it seems a rare event for others, but could be linked to the MTU setting and fragmenting packets.

I have carried out the advice on pinging packets and the result seems to be that I need my MTU set at 1496.

On my Mac it is currently:

Network > Advanced > TCP/IP Configure IPv4: Using DHCP

Network > Advanced > TCP/IP Configure IPv6: Automatically

Network > Advanced > Hardware Configure Automatically - this is where the MTU settings are set.

On my BT router for MTU it states: "The Hub defaults the MTU size to the optimum setting for your Broadband connection."

And it has set that to 1488

Do I have conflicts on the MTU setting? Would my Mac be automatically setting it to one thing, and the router another?

Help on this would be fanastic as it is causing serious issues for me.

Thanks in advance