VideoStudio 2018 Ultimate Stutters Playing Clip

[TexasNightOwl]

I have created smart proxy files for 4K mp4 files created by my Samsung S9 phone. If I play the videos by selecting Project they play fine. But if I select to play clip it stutters so bad it takes about 10 seconds to play 1 second worth of video. Likewise, if I select a clip on the timeline (which has a proxy and plays fine from the timeline) then select Multi-trim Video from the Edit menu it does the same stuttering as if I play clip.

It is as though the proxy file is not used for multi-trim video or for clip preview. The proxy seems to only get used when playing the project timeline.

I am using a new Lenovo Thinkpad X1 Carbon (6th gen) with I7-8550U, 16 GB RAM, 512 GB SSD.