REST API fatal error on save

When I try to save a post or page I get at 500 error

POST updated conten to
https://www.vem-co.com/wp-json/wp/v2/pages/1772?_locale=user

{
	"code": "internal_server_error",
	"message": "<p>There has been a critical error on this website.<\/p><p><a href=\"https:\/\/ww.wp.xz.cn\/documentation\/article\/faq-troubleshooting\/\">Learn more about troubleshooting WordPress.<\/a><\/p>",
	"data": {
		"status": 500,
		"error": {
			"type": 1,
			"message": "Uncaught TypeError: array_merge(): Argument #1 must be of type array, string given in \/public_html\/wp-content\/plugins\/sg-cachepress\/core\/Helper\/Update_Queue_Trait.php:22\nStack trace:\n#0 \/public_html\/wp-content\/plugins\/sg-cachepress\/core\/Helper\/Update_Queue_Trait.php(22): array_merge('', Array)\n#1 \/public_html\/wp-content\/plugins\/sg-cachepress\/core\/Supercacher\/Supercacher_Posts.php(178): SiteGround_Optimizer\\Supercacher\\Supercacher_Posts->update_queue(Array)\n#2 \/public_html\/wp-includes\/class-wp-hook.php(326): SiteGround_Optimizer\\Supercacher\\Supercacher_Posts->purge_all_post_cache(1772)\n#3 \/public_html\/wp-includes\/class-wp-hook.php(348): WP_Hook->apply_filters('', Array)\n#4 \/public_html\/wp-includes\/plugin.php(517): WP_Hook->do_action(Array)\n#5 \/public_html\/wp-includes\/post.php(5060): do_action('save_post', 1772, Object(WP_Post), true)\n#6 \/public_html\/wp-includes\/post.php(5162): wp_insert_post(Array, true, false)\n#7 \/public_html\/wp-includes\/rest-api\/endpoints\/class-wp-rest-posts-controller.php(946): wp_update_post(Array, true, false)\n#8 \/public_html\/wp-includes\/rest-api\/class-wp-rest-server.php(1292): WP_REST_Posts_Controller->update_item(Object(WP_REST_Request))\n#9 \/public_html\/wp-includes\/rest-api\/class-wp-rest-server.php(1125): WP_REST_Server->respond_to_request(Object(WP_REST_Request), '\/wp\/v2\/pages\/(?...', Array, NULL)\n#10 \/public_html\/wp-includes\/rest-api\/class-wp-rest-server.php(439): WP_REST_Server->dispatch(Object(WP_REST_Request))\n#11 \/public_html\/wp-includes\/rest-api.php(449): WP_REST_Server->serve_request('\/wp\/v2\/pages\/17...')\n#12 \/public_html\/wp-includes\/class-wp-hook.php(324): rest_api_loaded(Object(WP))\n#13 \/public_html\/wp-includes\/class-wp-hook.php(348): WP_Hook->apply_filters('', Array)\n#14 \/public_html\/wp-includes\/plugin.php(565): WP_Hook->do_action(Array)\n#15 \/public_html\/wp-includes\/class-wp.php(418): do_action_ref_array('parse_request', Array)\n#16 \/public_html\/wp-includes\/class-wp.php(813): WP->parse_request('')\n#17 \/public_html\/wp-includes\/functions.php(1336): WP->main('')\n#18 \/public_html\/wp-blog-header.php(16): wp()\n#19 \/public_html\/index.php(17): require('\/home\/customer\/...')\n#20 {main}\n  thrown",
			"file": "\/public_html\/wp-content\/plugins\/sg-cachepress\/core\/Helper\/Update_Queue_Trait.php",
			"line": 22
		}
	},
	"additional_errors": []
}