Led changes from white to orange - ac1750 r6700v3

> The printer is a canon pixma series mx920 WS.

   Ok.  As expected:

      https://www.usa.canon.com/internet/portal/us/home/support/details/printers/inkjet-multifunction/mx-series-inkjet/mx922?tab=manuals

      Wired LAN: 100BASE-TX/10BASE-T

That explains _its_ amber port-status LED.

> As far as I know. the orange means it is connected at 10/100 and the
> white means 1G.

   That's what the User Manual says.

> [...] Just a few seconds later the latop light turns orange. [...]

   I see no good reason for that change.  The LAN port speeds should
be negotiated independently.  If each port can be persuaded to run at
1000MHz under some circumstances, then my suspicions would lean toward
the firmware rather than the hardware.

> The firmware on my router is: V1.0.3.66_10.0.50

   I'd try something different/older.  It might not help, and might have
other problems of its own, but it'd be a reasonable experiment.

   Another interesting experiment would be to connect your devices to a
separate (cheap) gigabit Ethernet switch.  If they don't bother each
other when connected to a known-good switch, then you can be (more)
confident that the problem lies with the router, rather than with any of
your devices.

   If you still have any free support left, I'd contact Netgear, and
complain.  If not, but you still have remaining warranty, then you could
ask for a replacement.  Otherwise, a $15 switch might make a good
work-around while pondering what to get as your next router.