Artifacts in edited pictures in Photos

Editing pictures in Photos sometimes gives strange results. Approximately one out of fifteen pictures will have strange artifacts in them as shown below. When going back to the picture to edit, the artifact will usually disappear. Saving this edit might clear the problem or often it also comes back.

Unfortunately, the artifacts are also persistent in exported pictures, making anything edited useless.

The problem primarily seems to occur when editing multiple pictures in a row. It appears that Photos puts thumbnail generation in some sort of queue and that the artifacts occur because the system is overloaded somehow.

I have a Mac mini (Mid 2011, 2.3 GHz Intel Core i5, 16 GB 1600 MHz DDR3, Intel HD Graphics 3000 512 MB running macOS High Sierra version 10.13.1). Photos is running at version 3.0 (3231.11.210). The problem also occurred on Sierra, I actually hoped that upgrading to High Sierra, with the newest version of Photos, would solve the problem.

I have tried the following:

• Editing each picture, reverting to the original and recreating the edits. This is a hit and miss; sometimes it solves the problem, sometimes it does not.
• Repairing the Photos library as described here. This did not appear to help.

Any ideas what is causing this or how to solve it?