I think you probably have added a lot of CPFs and the PHP max_input_vars setting is being exceeded. I have made some tweaks to take the edge of it in
https://github.com/ocproducts/composr/commit/103895580d8da1fd929a6bf653a63c3f165b58c3

Try raising your max_input_vars setting via the .htaccess file (our default raises it to 2000).

I added 3 CPF's tied to a Group, but I will check on that setting to see what Bitnami Wampstack have set it to.

php_value max_input_vars 2000
php_value suhosin.get.max_vars 2000
php_value suhosin.post.max_vars 2000
php_value suhosin.request.max_vars 2000

added to .htaccess file and still no change to that setting when checked and saved, this is without the fixes being applied.

Can you catch me in IRC? This one is stumping me.

Investigation shows that the cns_get_all_custom_fields_match/cns_get_all_custom_fields_match_member functions need to take/default-to null for $special_start, and then accept both positive and negative checks when set to a binary value.

For this change to be made all calls to the functions will need to be assessed.