I just spoke with Litespeed support and they helped me allot to figure out many things. It's seems wp-stateless have some issues with last version of the litespeed cache.
``( ! ) Fatal error: Uncaught Error: Class 'LiteSpeed_Cache' not found in /var/www/html/wp-content/plugins/wp-stateless/lib/classes/compatibility/lite-speed-cache.php on line 84
( ! ) Error: Class 'LiteSpeed_Cache' not found in /var/www/html/wp-content/plugins/wp-stateless/lib/classes/compatibility/lite-speed-cache.php on line 84
Call Stack

Time Memory Function Location

1 0.0001 370784 {main}( ) .../admin.php:0
2 0.0001 371264 require_once( '/var/www/html/wp-load.php' ) .../admin.php:34
3 0.0001 371952 require_once( '/var/www/html/wp-config.php' ) .../wp-load.php:37
4 0.0001 373552 require_once( '/var/www/html/wp-settings.php' ) .../wp-config.php:35
5 0.1139 3757760 do_action( ) .../wp-settings.php:540
6 0.1139 3758136 WP_Hook->do_action( ) .../plugin.php:478
7 0.1139 3758136 WP_Hook->apply_filters( ) .../class-wp-hook.php:311
8 0.1540 5150432 LiteSpeed\Core->after_user_init( ) .../class-wp-hook.php:287
9 0.1561 5205336 LiteSpeed\Core->proceed_action( ) .../core.cls.php:221
10 0.1561 5205336 LiteSpeed\Router::handler( ) .../core.cls.php:273
11 0.1581 5502504 LiteSpeed\Img_Optm::handler( ) .../router.cls.php:701
12 0.1587 5553192 LiteSpeed\Img_Optm->pull( ) .../img-optm.cls.php:1847
13 0.2213 6229568 do_action( ) .../img-optm.cls.php:896
14 0.2213 6229944 WP_Hook->do_action( ) .../plugin.php:478
15 0.2213 6229944 WP_Hook->apply_filters( ) .../class-wp-hook.php:311
16 0.2214 6231072 wpCloud\StatelessMedia\LSCacheWP->sync_image( ) .../class-wp-hook.php:287
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instructions from Litespeed support ( I didn't tested yet - but, Ill do shortly ) $rm_ori_bkup = \LiteSpeed_Cache::config( \LiteSpeed_Cache_Config::OPT_MEDIA_RM_ORI_BKUP ) ;
is replaced with
$rm_ori_bkup = apply_filter('litespeed_conf', 'img_optm-rm_bkup' );
And for the rest of their code, the API is here: https://docs.litespeedtech.com/lscache/lscwp/api/
docs.litespeedtech.com
API | LSCache for WordPress | LiteSpeed Documentation
LiteSpeed Cache for WordPress API hook reference.`