Pfsense 2.3.1 p5 Draytek 2960 Ipsec keeps dropping and connecting

[MauricePot]

Hi,

I have a problem sinds last update.
The connection betweeen the Pfsense and Draytek 2960 drop and reconnect every 2-3 minutes sinds last update.
Also tried lowering MSS clamp, but that did also not work.
MTU=1452 now ans MSS tried from 1412 down till 1350.

See the Ipsec log file in the attachment.