iDrac Link going down for many other sites at the same time

Hi,

We have deployed dell r740 servers to many different geographical seperated DCs.

a few months ago, almost close dates iDrac access to hosts in different sites become to unreachable.

On some sites nearly half of the host iDrac access is lost.

We checked with our network team, the iDrac link braodcasts its MAC address to switch. Link between host and switch is up, but there is no ping.
When we re-seat cat6 cable on server idrac port, or shut - noshut the idrac linked port on switch, the access is fixed.

We raised a case to Dell as the common point here is servers are all same, after link is up again we access iDrac and get logs from servers, Dell Engineering team couldn't find a log related, as iDrac link seems ok on Server end.

On Switch side we have different Vendors and configs/Os on different sites. We couldn't understand what can be the root cause.

Is there any knowlegebase or articles about that issue?
How can we focus on root cause.

What we are planning to is disable-enable or issued ports from switches and will follow if it repeats. If repeats, we will need to understand root cause to be able to prevent from this failure next time.