Hi Chris
I’m sort of new to coding in After Effects myself so you’ll have to forgive and answer that will probably turn out to be no help at all.
If Motion blur is turned on at both the layer and composition;
It might be that Motion Blur on your composition is not be set high enough? You could right click on the Comp you are in check it’s Composition Settings and under the ‘Advanced’ tab check that it’s motion blur settings are high enough.
If they are:
Are you able to use a CC Force Motion Blur as an alternative?
Or (and I hate saying this) have you tried restarting AF or your CPU?
As for file collect. I don’t believe that saving updates the collected files. As far as I know you have to do a second file collect to update it.
Hope I was some help.
– Levi