Compilation failed / WordPress database error Illegal mix of collations

Hello,

I noticed the following error in our console which I think may be related to adding articles from Greek sites from what I can see the sites in the meta value:

[php7:notice] WordPress database error Illegal mix of collations (utf8_general_ci,IMPLICIT) and (utf8mb4_unicode_520_ci,COERCIBLE) for operation 'like' for query SELECT post_id FROM wp_postmeta WHERE post_id = 91940 AND meta_key = 'enclosure' AND meta_value LIKE 'https://omegalive.com.cy/kypros/\xce\xba\xce\xb1\xce\xb8\xce\xb7\xce\xb3\xce\xb7\xcf\x84\xce\xae\xcf\x82-\xce\xba\xce\xb1\xcf\x81\xce\xb1\xce\xb3\xce\xb9\xce\xac\xce\xbd\xce\xbd\xce\xb7\xcf\x82-\xcf%' /* From [<em>-site-</em>/wp-cron.php?doing_wp_cron=1611745458.7576169967651367187500] in [/nas/content/live/<em>-site-</em>/wp-cron.php:138] */ made by do_action_ref_array('do_pings'), WP_Hook->do_action, WP_Hook->apply_filters, do_all_pings, do_enclose, referer: <em>-site-</em>/wp-cron.php?doing_wp_cron=1611745458.7576169967651367187500

I enabled debug on our staging and when I tried adding the same article and I got this after sending it to draft:

Notice: Trying to access array offset on value of type int in /wp-content/plugins/pressforward/Core/Utility/Forward_Tools.php on line 574

Warning: copy(https://omegalive.com.cy/uploads/news/11Nov2020/kfgdfcbgfgkathkaraenavimmprgcfvgaragiannis.jpg): failed to open stream: HTTP request failed! HTTP/1.1 404 Not Found in /wp-content/plugins/pressforward/Core/Schema/Feed_Items.php on line 1044

It may be unrelated but when opening the nominate this tool for any article (greek or english)I see the following in the Nominate This box:

Warning: preg_match(): Compilation failed: invalid range in character class at offset 4 in /wp-content/plugins/pressforward/Libraries/PFSimpleHtmlDom.php on line 1081

Warning: preg_match_all(): Compilation failed: invalid range in character class at offset 4 in /wp-content/plugins/pressforward/Libraries/PFSimpleHtmlDom.php on line 587

Warning: Invalid argument supplied for foreach() in /wp-content/plugins/pressforward/Libraries/PFSimpleHtmlDom.php on line 593

Warning: preg_match_all(): Compilation failed: invalid range in character class at offset 4 in /wp-content/plugins/pressforward/Libraries/PFSimpleHtmlDom.php on line 587

Warning: Invalid argument supplied for foreach() in /wp-content/plugins/pressforward/Libraries/PFSimpleHtmlDom.php on line 593

Warning: preg_match_all(): Compilation failed: invalid range in character class at offset 4 in /wp-content/plugins/pressforward/Libraries/PFSimpleHtmlDom.php on line 587

Warning: Invalid argument supplied for foreach() in /wp-content/plugins/pressforward/Libraries/PFSimpleHtmlDom.php on line 593

Warning: preg_match_all(): Compilation failed: invalid range in character class at offset 4 in /wp-content/plugins/pressforward/Libraries/PFSimpleHtmlDom.php on line 587

Warning: Invalid argument supplied for foreach() in /wp-content/plugins/pressforward/Libraries/PFSimpleHtmlDom.php on line 593

Warning: preg_match_all(): Compilation failed: invalid range in character class at offset 4 in /wp-content/plugins/pressforward/Libraries/PFSimpleHtmlDom.php on line 587

Warning: Invalid argument supplied for foreach() in /wp-content/plugins/pressforward/Libraries/PFSimpleHtmlDom.php on line 593

Warning: preg_match_all(): Compilation failed: invalid range in character class at offset 4 in /wp-content/plugins/pressforward/Libraries/PFSimpleHtmlDom.php on line 587

Warning: Invalid argument supplied for foreach() in /wp-content/plugins/pressforward/Libraries/PFSimpleHtmlDom.php on line 593

Warning: preg_match_all(): Compilation failed: invalid range in character class at offset 4 in /wp-content/plugins/pressforward/Libraries/PFSimpleHtmlDom.php on line 587

Warning: Invalid argument supplied for foreach() in /wp-content/plugins/pressforward/Libraries/PFSimpleHtmlDom.php on line 593

Any input/advice would be very much appreciated!