problem. causeing json /api errors

good morning I’m getting this message in my redirect plugin after installing the tag manager…
I’ve isolated the issue. ( if I deactivate tag manger it goes away).
is there any workaround or fix you can suggest… ?

Plugin: 5.1.3 4.2
WordPress: 5.8 (single)
PHP: 7.4.23
Browser: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.159 Safari/537.36
JavaScript: https://www.staging7.jbhunter.edu.au/wp-content/plugins/redirection/redirection.js?ver=5.1.3-81f455fc2a8faec560fb955b29f9a717
REST API: https://www.staging7.jbhunter.edu.au/wp-json/
Query: ?page=redirection.php&sub=options

Error: Unexpected token < in JSON at position 2 (SyntaxError)
Raw: 

<!-- Google Tag Manager (noscript) -->{"settings":{"support":false,"token":"8ce54bd6d745ba0f8bda4efb85d03dda","monitor_post":0,"monitor_types":[],"associated_redirect":"","auto_target":"","expire_redirect":7,"expire_404":1,"modules":{"2":{"location":""}},"newsletter":false,"redirect_cache":1,"ip_logging":1,"last_group_id":1,"rest_api":0,"https":false,"database":"4.2","flag_query":"exact","flag_case":false,"flag_trailing":false,"flag_regex":false,"headers":[],"relocate":"","preferred_domain":"","aliases":[],"log_external":false,"log_header":false,"track_hits":true,"permalinks":[],"cache_key":0,"plugin_update":"prompt","update_notice":"5.1","location":""},"groups":[{"label":"WordPress","value":[{"label":"Redirections","value":1},{"label":"Modified Posts","value":2}]}],"installed":"\/home\/customer\/www\/staging7.jbhunter.edu.au\/public_html\/","canDelete":true,"post_types":{"post":"Posts","page":"Pages","portfolio_page":"Portfolio","product":"Products","trash":"Trash"}}

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