Warning on all websites dashboard

when visiting all websites dashboard…
we get this message showing up 30 times
WARNING: …/core/Piwik.php(138): Notice - A non well formed numeric value encountered - AiMG Analytics 3.13.2 - Please report this message in the AiMG Analytics forums: https://forum.matomo.org (please do a search first as it might have been reported already) (Module: CustomReports, Action: getCustomReport, In CLI mode: false)