nighthawk CM1200 will not load most pictures and videos from facebook

[oldmom]

Most pictures and videos in Facebook and Instagram do not load. When wifi is turned off, they load immediately on cellular.  I have tried a reboot and firmware is up to date.  

[antinode]

> Model: CM1200|Nighthawk Multi-Gig Speed Cable Modem

   A CM1200 is a modem.  As such, it's generally too stupid to block
anything.  It also has no wireless capability.  Perhaps your
(innocent-bystander) modem is connected to some (potential-culprit)
router or other, which might be smart enough to cause the trouble you're
seeing.

> [...] I have tried a reboot [...]

   "a reboot" of _what_?

> [...] and firmware is up to date.

   "firmware" of _what_?  As always, an actual version number would be
more useful than your opinion of what's "up to date" today.  (On
whatever it is.)

[antinode]

      https://community.netgear.com/t5/x/x/m-p/2129622

   Starting multiple threads for one problem is seldom maximally
efficient.