if (filter_var(APP_VERSION, FILTER_SANITIZE_NUMBER_INT) < filter_var($value->title, FILTER_SANITIZE_NUMBER_INT))

This was a flawed condition, for example, this statement was changing Version 1.0.46 to 1046 and comparing to Version 1.2.6, as 126. i.e. if (1046 < 126) which is incorrect.

Switched to version_compare(), so that now it is comparing 1.0.46 & 1.2.6

if (version_compare($applications_version, trim($value->title, 'Kanboard ')) < 0)

Actually that is flawed too, I noticed Fred Guillot doesn't always Title with Kanboard , sometimes he uses Kanboard Version.

This one works always:

if (version_compare($applications_version, trim(preg_replace('/[A-Za-z]/', '', $value->title), ' ')) < 0)