Experiencing flickering video clips in Final Cut Pro X.

Hello everyone,
Thank you for accepting me into this forum. Please forgive my imperfect English. I'd like to share my problem with you. I created a moving path on a map using Apple Motion, which is essentially a colored line depicting a route on a map. I exported it as a *.mov video file and imported it into Final Cut Pro's media. I inserted it into a timeline where I already had a project with *.mp4 video files (a photo slideshow created with Keynote).
When I play the timeline preview, the part with the track on the map flickers significantly. I thought this might be due to the two different formats. The Keynote video is in Mpeg4 format, 1440x1080 resolution, H264 codec, and the frame rate isn't indicated to me. The video of the map created with Motion is in 1024x768 resolution, Apple ProRes codec, with a frame rate of 30 fps.
The final video I need to create doesn't have specific resolution requirements. I'll be presenting it using a laptop and a projector with a maximum resolution of 1024x768.
I appreciate your assistance in resolving this issue. Thank you.

I'd try exporting the Keynote video again, this time as Custom/ProRes. The quick H.264 exports can end up as variable frame rate files which do not play well in any NLE.

In the Keynote Export panel, set the Resolution to Custom, enter the resolution that you actually want, set your frame rate, and use ProRes 422.