After updating to Soledad 8.0.8 all featured images are missing on my site.
(For the time being, the site is running on localhost under XAMPP only). 

There is no "Penci PageSpeed Optimizer" plugin in the list of installed plugins.

I tried updating "Penci Shortcodes & Performance" (version 4.1 now), clearing the browser cache, increasing post_max_size (to 120M) and memory_limit (to 1024M) in php.ini - all without any effect.

Do you have any further suggestions what I could do?

Thank you!

The problem seems to occur only for "List posts" (see screenshot).
 In other post layouts (e.g. "Small list posts") the images display correctly.

These plugins are active on my site:

Vafpress Post Formats UI
UpdraftPlus
Ultimate Blocks
TablePress Extension: Responsive Tables
TablePress
SVG Support
Penci Slider
Penci Shortcodes & Performance
ICS Calendar
Font Awesome
FileBird Lite
Email Encoder - Protect Email Addresses

I don't thinkt that there is one with a lazy load feature.

I found the problem - and it was entirely caused by myself:

In my child theme I was using a slightly modified version of content-list.php which is no longer working with the current version of soledad. 

Thank you for your time and your kind help!