Try fooling with the value for --dpd-idle
--dpd-idle <0,10-86400> DPD idle timeout (our side) <0,10-86400> Send DPD packet after not receiving anything for <idle> seconds. Use 0 to disable DPD completely (both ways). Default: 300
i.e.
In your config file have the line:
DPD idle timeout (our side) 0
(to disable it)
Try fooling with the value for --dpd-idle
--dpd-idle <0,10-86400>
DPD idle timeout (our side) <0,10-86400>
Send DPD packet after not receiving anything for <idle> seconds.
Use 0 to disable DPD completely (both ways).
Default: 300
i.e.
In your config file have the line:
DPD idle timeout (our side) 0
(to disable it)