Meraki MX84 uplink keeps flapping Duplex

[karandash]

We are having issue with Meraki MX84 uplink every two weeks or so where we get about 25% packet loss which keeps growing. Reached out to ISP and they show incomplete frames with CRC errors which would indicate that one end is set to half duplex. ISP sets their side to full duplex and so do we. I have swapped out the cable, switched port to half duplex and then back to full and packet loss dropped to 0%. However 2 weeks later we see the same behavior. Has anyone seen this issue before? Would this indicate FW going bad? Thanks in advance! 

[BlakeRichardson]

@karandash What version of firmware are you using on the MX and have you tried a different version? 

[GIdenJoe]

Hmm, I had issues with certain ISP modems and MX84 too.
You might wanna try connecting your MX WAN via a switch on an external VLAN and see if the problem returns and on which port (the one leading to the MX or the one leading to the ISP router/modem.

[PhilipDAth]

Are you using a current stable or stable release candidate image?

[cmr]

I would ask the ISP to set auto and set the same yourself.  Always been more reliable for me.