Often users have noticed the feature of thumbnail preview not set by default in their Windows 10 operating systems. This is normal and not a bug, so if you are scavenging over the internet looking for “fixes”, you won’t find working ones
PowerToys File Explorer add-ons enable preview pane and thumbnail renderers for SVG, PDF, Markdown, and source code files in Windows. Download and configure these utilities to enhance your file browsing experience.
SageThumbs is a powerful shell extension allowing to preview enormous amount of image formats directly in Windows Explorer by using Pierre-e Gougelet's GFL library (XnView's author).
Thumbcache Viewer allows you to extract thumbnail images from the thumbcache_*.db and iconcache_*.db database files found on Windows Vista, Windows 7, Windows 8, Windows 8.1, Windows 10, and Windows 11.