[BenRogers001]

I bought this CNC router new (Freedom Machine Tool, 5x10, 10hp Hiteco Spindle) about 18 months ago.
Early on, the tool holders and spindle taper started to show a lot of "fretting" wear, which seems to be caused by excessive vibration between the tapers, see the attached photos.
I don't have a ton of hours running the machine, it runs 1 or 2 days a week.
I've tried to diagnose the problem, and my current theory is that it's a simple feed/speed issue, but I wanted to get your opinions on it.
I use 3/8" Amana down-spiral router bits, cutting 3/4" plywood at 300ipm, 18000 rpms, and around 0.7" depth of cut (I cut in 2 passes, a rough and finish).
According to the Amana spec sheet, this feedrate is a little high, but the machine handles it without any issue and I've never broken a tool.
Are these feeds & speeds unreasonable? And could they be the cause of this crazy fretting, or should I look elsewhere?

This issue is causing me so much stress, if anyone has any input or ideas it would be highly appreciated.

Thank you.