FS-148E and FS-124E - Large Percentage of Errors on SFP Ports

I have recently purchased two Fortinet switches, an FS-124E and an FS-148E, and deployed them in my network at separate locations. I am seeing a large percentage of packet drops (about 30%), specifically inbound discards. These errors are usually indicative of a lack of available packet receive buffers. This can indicate that the device's internal CPU may be unable to process all of the inbound data that it is receiving. Both switches have a single connection to a Cisco 3750X and I detect no errors on these ports. Both Fortinet switches are running firmware version v6.2.1,build0176,190620 (GA) with Fortinet recommended transceivers.

Has anyone experienced a similar issue?