Images and Icons wont load in Jenkins

Question

I have upgraded jenkins to 2.319.1 and started seeing this issue. Our Jenkins is accessed via Netscaler endpoint. https://company.internal.com/jenkins.
Earlier I used to access via host:8080 format. i.e http://host:8080/jenkins and everything was working. It still works fine when accessed like that.

Image 1 : When accessed via Netscaler

Image 2 : When accessed via ip

What I tried so far.

1. I have checked the logs. No info in logs. Hence I suspect this may be Netscaler's doing.
2. I tried using Nginx for reverse proxy and it works fine.
3. I tried simple theme to put custom images and icons. It wont work.

Are there any plugins which can provide icons.I have tried dark theme and simple theme plugins, but to no avail.

Update : I narrowed down the last working version

LTS : https://archives.jenkins-ci.org/redhat-stable/jenkins-2.303.3-1.1.noarch.rpm

Regular : https://archives.jenkins-ci.org/redhat/jenkins-2.307-1.1.noarch.rpm

Update 2

svgs are present in /var/cache/jenkins/images folder. They wont load in browser.

Answer 1

Finally we found the solution. We had a http to https redirection policy in Netscaler. We dont know why that was blocking *.svg images. The policy is turned off and now jenkins is working great.All the images are loading properly and functionality is working fine.

Answer 2

Update the plugins.

For me what worked was that I hadn't updated the plugins. As soon as I did that all the icons were available.