Connection issue when connect from outside to Pilot

Hi all,
Istio version 1.10.3
we have a issue while connecting from outside to pilot.
After a while the connection is closed and not restored .
when we restart the ingress the connenction works fine
I suspect the issue with the Istio ingress , checked the CDS/LDS/EDS/RDS/STIOD

istioctl proxy-status

NAME CDS LDS EDS RDS ISTIOD VERSION
istio-egressgateway-78d75d8868-95znd.istio-system SYNCED SYNCED SYNCED NOT SENT istiod-7b7587d6fd-6rtf8 1.10.3
istio-ingressgateway-5c5499b774-kfz49.istio-system SYNCED SYNCED SYNCED SYNCED istiod-7b7587d6fd-6rtf8 1.10.3

what should be checked /changed to solve it?
Thanks in advance