have just released a development version (3.1.d.1) , which includes multiple fixes, particularly on the past profitability calculation.
You can get it here: https://www.rigmonitor.app/blog/downloads/

3.1.d.1 (development)
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-Added check for number of rigList and poolList configuration items
-Updated whattomine url to use https
-Fixed issue (#54) with "INVALID SHARES REPORTED BY RIG" not starting at 0
-Fixed issue (#53) with "VALID SHARES REPORTED BY RIG" not honoring selected pool
-Fixed issue with time/day boundaries used in past profitabily calculation
-Fixed issue with TLS/SSL errors when connecting to whattomine.com