tbs6902 and tvheadend

Hello, i have one question.
Why tbs6902 not show correctly signal strengh like example in attachment. Signal is locked and not update, when option "force old status" is unchecked. When I check this option "db" and "dbm" is now "%" and start to update every 5 seconds (time I set in my configuration).
Why tbs6902 not show correctly signal strengh like example in attachment. Signal is locked and not update, when option "force old status" is unchecked. When I check this option "db" and "dbm" is now "%" and start to update every 5 seconds (time I set in my configuration).