Here is a picture of your issue
Here is the rule for CTWUG highsite
126.96.36.199. Signal strengths must exceed -73 dBm for new clients to connect.
188.8.131.52. Signal strengths must exceed -75 dBm for existing clients to remain connected.
184.108.40.206. Clients must maintain a 95th percentile CCQ of 60% or higher in both directions to remain connected.
Reason why we have this rule is to ensure that clients have a decent to good connection. Your is signal is mid to high 80's.
So what can you do to improve your link, first try to align your antenna to an acceptable level. Please post results here.