Error in accessing SharePoint designer 2013


I’m having a SharePoint 2016 with 2 WFE servers say, Server A and Server B.

When i tried accessing the SharePoint designer 2013, to edit the site pages. I’m getting the two kinds of errors, mentioned in the following screenshots.

enter image description here

enter image description here

on my investigation i found that something is not correct with the servers, hence i switched off one of my WFE server – Sever A , and worked with only server B, Now I can access the site without any issues. It worked well. Then i tried vice versa, now ,the issue repeated again. Hence i conclude that the issue is with Server A.

After that i checked the IIS settings , windows firewall, windows updates, SharePoint updates and even Load balancer configurations, everything were seems to be correct and as same as my sever B. so I’m unable to find what is wrong with my server A.

Also, I’m facing some HTML5 page loading issue in my site, which is also related to this server A issue. I’ve swtiched off Server A and accessed the page, it worked well. Otherwiser those pages will not load. on several refreshes those pages will load. So this is also an issue with server A.

So anyone please help me to find out what is wrong with my Server A and how to fix it.

Thanks in Advance.