what is orbi's tcp session timeout value?

i wish i could edit older posts so information could be better presented.  the guy in the other thread has a 'better' gateway than mine in terms of performance and features.

ive got a pace 5031NV-030 from 2016.  it has a firmware log that show initial and current firmware.  both are the same.  about two weeks ago, i called att and one of the actions they took was to reflash the firmware.  needless to say, internet connectivity/stability did not improve.  this particular device only does phone and internet.  internal wifi is 2.4N (currently disabled). i am not subscribed to the phone service.  max rate in my area is 45mbps. i was at the 24mbps rate until yesterday.  when i found the tcp session timeout improved stability, i reduced service to 18mbps to save a few dollars.  

tcp session timeout at the pace gateway. one should reset both the gateway and orbi or wait more than a few hours for the changes to settle.

1800 seconds: tried this for five/six days with no issues. at least no family members complained.

7500 seconds: 24 hours, so far so good. i know i the orbi is at 7440.

86400 seconds: default value.  loss of internet at sporadic intervals.

gateway -> settings -> firewall -> applications, pinholes and dmz or http://192.168.1.254/xslt?PAGE=C_3_1
gateway -> firewall -> advanced configuration -> tcp session timeout or http://192.168.1.254/xslt?PAGE=C_3_2
gateway -> settings -> diagnostics -> nat -> total sessions in use or http://192.168.1.254/xslt?PAGE=C_5_5

i believe the internet service disruption is caused by the isp gateway being overloaded. the cause is the tcp session timeout value being grossly miss-matched between the two devices when the isp gateway has to do NAT or PAT. i guess it is not yet possible for the downstream router to self adjust to the isp gateway timeout.

i wonder if those who changed to other mesh solutions got lucky and that unit happened to have matching tcp session timeout values.