You will probably have to use more sophisticated tools like RevisionFX RE:Match to get better temporal smoothing. Anyway, without actualyl seeing a snippet of the footage with and without the treatment for comaprison, nobody can really tell you much. Perhaps it can be remedied wit ha subtle timewarp or so to average the frames a bit and thus stabilize the automatic color adjustments, but we realyl can't know...
A sample of the video - no effect added - is at:
With the effect and flicker:
After a bit more experimenting, I have found a solution. I used the CC Time Blend effect. It does create an interesting trails efefct when there is a lot of movement. But, the speaker is mostly static. I applied a mask to the screen as its quality is high throughout.
The new version is at:
May still need to tweak the settinngs but for the purpose of this video, I'm happy with the result.