It seems odd that a voice mailbox is signaling to your OBi202 to indicate visually and by stutter tone on both phone ports but then will not signal to clear these indicators. If this is so, then this suggests your equipment may be working and the signal from your voice mailbox may be suspect. Have you contacted your service provider? Are your calls communicating fully otherwise... no router issues? Sorry, I don't understand the one-way signaling...
OE