[Resolved] WPML Fatal Error with PHP 8.0 / 8.1 (Fatal error: Uncaught TypeError)

Hi,
When I update my server (godaddy) from php 7.4 to php 8.0 or 8.1, i get a php Fatal error on the frontend (debug mode).

I am using all the latest versions for my plugins and wordpress, including the latest WPML plugin / wpml addons versions.

If i switch theme to use a wordpress default theme AND deactivate all plugins except keeping only the WPML and WPML addons active, then I still get the fatal error.

If I deactivate specifically only WPML String Translation, then this solves the fatal error with php 8. I also notice that if I am using php 7.4 and go to WPML > String Translation in the admin, i get a blank page with this error :
Warning: Illegal string offset 'WPML\ST\Batch\Translation\Records_schema_installed' in /var/www/wp-content/plugins/sitepress-multilingual-cms/vendor/wpml/core-api/core/OptionManager.php on line 45
(Note: this means with php 7.4 I am unable to use string translation, and when I activate php 8.x then i cannot access wordpress admin at all due to Fatal error).

I setup a staging site to do testing (9nl.869.myftpupload.com), currently the staging is set to php 8.0 with all my normal theme/plugin active and string translation also active, therefore you will see the error on the frontend, here is a copy of the error text:

Fatal error: Uncaught TypeError: Cannot access offset of type string on string in /var/www/wp-content/plugins/sitepress-multilingual-cms/vendor/wpml/core-api/core/OptionManager.php:45 Stack trace: #0 /var/www/wp-content/plugins/wpml-string-translation/classes/batch-translation/Records.php(62): WPML\WP\OptionManager->set('ST', 'WPML\\ST\\Batch\\T...', true) #1 [internal function]: WPML\ST\Batch\Translation\Records::WPML\ST\Batch\Translation\{closure}(Object(wpdb)) #2 /var/www/wp-content/plugins/sitepress-multilingual-cms/vendor/wpml/fp/core/functions.php(154): call_user_func_array(Object(Closure), Array) #3 [internal function]: WPML\FP\{closure}(Object(wpdb)) #4 /var/www/wp-content/plugins/sitepress-multilingual-cms/vendor/wpml/fp/core/traits/Curryable.php(57): call_user_func_array(Object(Closure), Array) #5 /var/www/wp-content/plugins/wpml-string-translation/classes/batch-translation/Module.php(30): WPML\ST\Batch\Translation\Records::__callStatic('installSchema', Array) #6 /var/www/wp-content/plugins/wpml-string-translation/plugin.php(64): WPML\ST\Batch\Translation\Module::init() #7 /var/www/wp-includes/class-wp-hook.php(310): wpml_st_core_loaded(Object(SitePress)) #8 /var/www/wp-includes/class-wp-hook.php(334): WP_Hook->apply_filters(NULL, Array) #9 /var/www/wp-includes/plugin.php(517): WP_Hook->do_action(Array) #10 /var/www/wp-content/plugins/sitepress-multilingual-cms/sitepress.class.php(523): do_action('wpml_loaded', Object(SitePress)) #11 /var/www/wp-includes/class-wp-hook.php(310): SitePress->init('') #12 /var/www/wp-includes/class-wp-hook.php(334): WP_Hook->apply_filters(NULL, Array) #13 /var/www/wp-includes/plugin.php(517): WP_Hook->do_action(Array) #14 /var/www/wp-settings.php(495): do_action('plugins_loaded') #15 /var/www/wp-config.php(103): require_once('/var/www/wp-set...') #16 /var/www/wp-load.php(50): require_once('/var/www/wp-con...') #17 /var/www/wp-blog-header.php(13): require_once('/var/www/wp-loa...') #18 /var/www/index.php(17): require('/var/www/wp-blo...') #19 {main} thrown in /var/www/wp-content/plugins/sitepress-multilingual-cms/vendor/wpml/core-api/core/OptionManager.php on line 45