A lot of Invalid session or Session timeout

Hi, I have a lot of Invalid session or Session timeout,what can i do? the phones every 600s connect to the acs

2020-03-19T02:38:45.733Z [ERROR] 000B82-GXP1625-000b82d46d81: Session timeout; sessionTimestamp=1584585494572
2020-03-19T02:38:45.845Z [ERROR] 000B82-GXP1405-000b8261efee: Session timeout; sessionTimestamp=1584585494837
2020-03-19T02:38:47.443Z [ERROR] Invalid session
2020-03-19T02:38:47.460Z [ERROR] Invalid session
2020-03-19T02:38:47.472Z [ERROR] Invalid session
2020-03-19T02:38:47.476Z [ERROR] Invalid session
2020-03-19T02:38:47.531Z [ERROR] Invalid session
2020-03-19T02:38:47.537Z [ERROR] Invalid session
2020-03-19T02:39:19.860Z [ERROR] 000B82-GXP1625-000b82e77af1: Session timeout; sessionTimestamp=1584585499773
2020-03-19T02:39:47.452Z [ERROR] Invalid session
2020-03-19T02:39:47.495Z [ERROR] Invalid session
2020-03-19T02:40:19.326Z [ERROR] Invalid session
2020-03-19T02:40:19.436Z [ERROR] Invalid session
2020-03-19T02:40:19.505Z [ERROR] Invalid session

This is an issue where the end client isn’t properly closing the connection. I would raise the issue with your vendor.

thanks. from the debug log 13:50:48 the client has not send request.
I want to make sure this error is not my acs server problem?or can I set something in my acs server?