Playhead pauses at every transition

I’m trying to create a video from a couple of dozen still images.
All images are TIFF, 16:9 aspect ratio.
I loaded all images by clicking Ctrl-O and selecting all from the same folder.
I added all to the playlist.
I added the entire playlist to the timeline. Duration for each was preset at 5 seconds.
No images were moved or altered after being added to the timeline.
I added an audio track and added music to it.
When I play the timeline (to check everything before exporting), the playhead pauses for about 1/2 second at each transition (end of each image and start of next image). This also creates pauses in the audio, which stops at each pause.
What could be causing this? I haven’t had this problem before.

This is normal for playback while editing as nothing has been rendered yet, especially for TIFF which are either compressed or very large. Your PC is probably struggling to handle the ‘on-the-fly’ transition. It will play just fine once rendered and encoded.

"It will play just fine once rendered and encoded."
You are right; thanks!
I will try batch processing all TIFF files to 1920x1080 Jpegs prior to opening in Shotcut, to see if that helps, to make the final proof-viewing easier.