Packet Loss

I appreciate any feedback! My ISP has a 3400 connected via MM fiber to an EtherNID. I run a ping to an external IP [and] a ping to the inside interface that connects the 3400 to my LAN (copper). The host computer is Hardwired from the same LAN switch the 3400 is plugged into.

-HOST PC(hardwire)->LAN Switch

-3400 (copper)->LAN Switch

-EtherNID(MM Fiber)->3400->ISP Backbone (1 gig connection)

Im dropping packets randomly every 3,5,7 12th packets on both pings.

- The 3400, copper optic, fiber optic, and fiber Patch Cable have been replaced.

-EtherNID, SM Fiber Patch cable and optic are not new. Yet to be replaced.

***As soon as i unplug the fiber connecting the 3400 to the EtherNID, WAN connection, the ping from the host computer to the 3400 inside interface straightens out and there is no packet loss. As soon as I restore the WAN connection i start dropping packets to the 3400 inside int. and to the internet.

Question:

1)Is it normal to be dropping packets like this to both the router inside interface and to the outside.

2)Why do the packets straighten out when the WAN Connection is pulled

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Thank you kindly