bypass_cache filter

Hi,
I continue having cache issue with my cookie banner. I try to exclude stm_gdpr_cookie as suggest my GDPR plugin author, but if I exclude this cookie I exclude all my site page from caching. (if I understand right)
I try to exclude entire plugin, but it seems this isn’t possible.
So I’m trying to use bypass_cache filter but, it seems it doesn’t work properly.

I added this row to my function.php file:
add_filter( 'bypass_cache', 'displayPopup' )
where displayPopup is the GDPR plugin function that manage cookie popup.

result:
1# with “Pre-compression of cached pages” (in cache enabler settings) activated, popup never appears and my site doesn’t release cookies.
2# with “Pre-compression of cached pages” deactivated nothing changes. The popup appear at the first access(site serves a not cached page). If I accept cookie consent, popup desappears but it reappers when I return on first access page(site serves a cached page with popup).

Is there something I’m doing wrong?

Please note that this is a cache enabler issue beacause if I deactivate plugin all work properly and GDPR plugin author said me that all customers are using this plugin without issue simly excluding cookie plugin from cache plugin….

thank you very much
regards

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