https://wordpress.org/support/topic/optimized-unsmushed-pictures-just-spins-forever/
This is obviously THE superb optimiser plugin out there in 2020. However, I still have the aforementioned issue. This still needs to be referenced in 2020. The clock icon keeps spinning without progress bar progressing, or the progress bar stalls at certain percent.
Need to thank https://wordpress.org/support/users/joeinfo/ for pushing this issue to be heard.
Please re-open the topic so it can be referenced with further solutions:
https://wordpress.org/support/topic/optimized-unsmushed-pictures-just-spins-forever/