Hi Karl
Tagging in on this I am having similar problems.
I have enabled google docs viewer but still not getting a "thumbnail version" showing in the folder though on clicking the viewer works perfectly okay. Test result shared here for you.
Files Gallery 0.10.2
ratsoftobruk.com.au
PHP 7.4.33
LiteSpeed
root
storage_path
index.php
gd
exif
mbstring
ZipArchive
mime_content_type()
finfo_file()
iptcparse()
exif_imagetype()
session_start()
ini_get()
exec()
memory_limit 256M
file_uploads 1
upload_max_filesize 128M
post_max_size 128M
max_file_uploads 20
Config
<?php
return array (
'root' => '',
'root_url_path' => NULL,
'start_path' => false,
'username' => '',
'password' => '',
'load_images' => true,
'load_files_proxy_php' => false,
'load_images_max_filesize' => 1000000,
'image_resize_enabled' => true,
'image_resize_cache' => true,
'image_resize_dimensions' => 320,
'image_resize_dimensions_retina' => 480,
'image_resize_dimensions_allowed' => '',
'image_resize_types' => 'jpeg, png, gif, webp, bmp, avif',
'image_resize_quality' => 85,
'image_resize_function' => 'imagecopyresampled',
'image_resize_sharpen' => true,
'image_resize_memory_limit' => 1024,
'image_resize_max_pixels' => 0,
'image_resize_min_ratio' => 1.5,
'image_resize_cache_direct' => true,
'folder_preview_image' => true,
'folder_preview_default' => '_filespreview.jpg',
'menu_max_depth' => 5,
'menu_sort' => 'name_asc',
'menu_cache_validate' => false,
'menu_load_all' => false,
'menu_recursive_symlinks' => true,
'layout' => 'blocks',
'cache' => true,
'cache_key' => 0,
'storage_path' => '***',
'files_exclude' => '',
'dirs_exclude' => '',
'allow_symlinks' => true,
'get_mime_type' => false,
'license_key' => '',
'filter_live' => true,
'filter_props' => 'name, filetype, mime, features, title',
'download_dir' => 'browser',
'download_dir_cache' => 'dir',
'assets' => '',
'allow_upload' => true,
'allow_delete' => false,
'allow_rename' => false,
'allow_new_folder' => false,
'allow_new_file' => false,
'allow_duplicate' => false,
'allow_text_edit' => false,
'allow_zip' => false,
'allow_unzip' => false,
'allow_move' => false,
'allow_copy' => false,
'allow_download' => true,
'allow_mass_download' => false,
'allow_mass_copy_links' => false,
'allow_check_updates' => false,
'allow_tests' => true,
'allow_tasks' => false,
'demo_mode' => false,
'video_thumbs' => true,
'video_ffmpeg_path' => 'ffmpeg',
'pdf_thumbs' => true,
'imagemagick_path' => 'convert',
'use_google_docs_viewer' => true,
'lang_default' => 'en',
'lang_auto' => true,
);