Unable to install any plugins on the jenkins ubuntu instance. 
Jenkins is trying to download the plugins from the below link, but fails to with read timeout exception

https://updates.jenkins.io/download/plugins/cloudbees-folder/6.15/cloudbees-folder.hpi

When I hit the above link in browser, I either get 504 Gateway timout error ot 404 Not-Fount Exception.

Exception stack trace:

2020-11-13 00:55:34.977+0000 [id=68] INFO h.model.UpdateCenter$DownloadJob#run: Starting the installation of workflow-api on behalf of admin2020-11-13 00:55:34.977+0000 [id=68] INFO h.model.UpdateCenter$DownloadJob#run: Starting the installation of workflow-api on behalf of admin2020-11-13 00:56:35.035+0000 [id=68] INFO h.m.UpdateCenter$UpdateCenterConfiguration#download: Downloading workflow-api2020-11-13 00:56:35.036+0000 [id=68] SEVERE h.model.UpdateCenter$DownloadJob#run: Failed to install workflow-apijava.net.SocketTimeoutException: Read timed out at java.net.SocketInputStream.socketRead0(Native Method) at java.net.SocketInputStream.socketRead(SocketInputStream.java:116) at java.net.SocketInputStream.read(SocketInputStream.java:171) at java.net.SocketInputStream.read(SocketInputStream.java:141) at sun.security.ssl.SSLSocketInputRecord.read(SSLSocketInputRecord.java:457) at sun.security.ssl.SSLSocketInputRecord.bytesInCompletePacket(SSLSocketInputRecord.java:68) at sun.security.ssl.SSLSocketImpl.readApplicationRecord(SSLSocketImpl.java:1095) at sun.security.ssl.SSLSocketImpl.access$200(SSLSocketImpl.java:72) at sun.security.ssl.SSLSocketImpl$AppInputStream.read(SSLSocketImpl.java:815) at java.io.BufferedInputStream.fill(BufferedInputStream.java:246) at java.io.BufferedInputStream.read1(BufferedInputStream.java:286) at java.io.BufferedInputStream.read(BufferedInputStream.java:345) at sun.net.www.http.HttpClient.parseHTTPHeader(HttpClient.java:735) at sun.net.www.http.HttpClient.parseHTTP(HttpClient.java:678) at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1593) at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1498) at sun.net.www.protocol.http.HttpURLConnection.getHeaderField(HttpURLConnection.java:3061) at java.net.URLConnection.getHeaderFieldLong(URLConnection.java:629) at java.net.URLConnection.getContentLengthLong(URLConnection.java:501) at java.net.URLConnection.getContentLength(URLConnection.java:485) at sun.net.www.protocol.https.HttpsURLConnectionImpl.getContentLength(HttpsURLConnectionImpl.java:412) at hudson.model.UpdateCenter$UpdateCenterConfiguration.download(UpdateCenter.java:1264)Caused: java.net.SocketTimeoutException: Read timed out at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) at sun.net.www.protocol.http.HttpURLConnection$10.run(HttpURLConnection.java:1950) at sun.net.www.protocol.http.HttpURLConnection$10.run(HttpURLConnection.java:1945) at java.security.AccessController.doPrivileged(Native Method) at sun.net.www.protocol.http.HttpURLConnection.getChainedException(HttpURLConnection.java:1944) at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1514) at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1498) at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:268) at hudson.model.UpdateCenter$UpdateCenterConfiguration.download(UpdateCenter.java:1280)Caused: java.io.IOException: Failed to load https://updates.jenkins.io/download/plugins/workflow-api/2.40/workflow-api.hpi to /var/lib/jenkins/plugins/workflow-api.jpi.tmp at hudson.model.UpdateCenter$UpdateCenterConfiguration.download(UpdateCenter.java:1287)Caused: java.io.IOException: Failed to download from https://updates.jenkins.io/download/plugins/workflow-api/2.40/workflow-api.hpi (redirected to: https://get.jenkins.io/plugins/workflow-api/2.40/workflow-api.hpi) at hudson.model.UpdateCenter$UpdateCenterConfiguration.download(UpdateCenter.java:1321) at hudson.model.UpdateCenter$DownloadJob._run(UpdateCenter.java:1869) at hudson.model.UpdateCenter$InstallationJob._run(UpdateCenter.java:2147) at hudson.model.UpdateCenter$DownloadJob.run(UpdateCenter.java:1843) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at hudson.remoting.AtmostOneThreadExecutor$Worker.run(AtmostOneThreadExecutor.java:118) at java.lang.Thread.run(Thread.java:748)