This article explains the behaviour of the hold-interval attribute configured for dynamic list.

You might see SRX failing to refresh the EDL from the server but the EDL entries are not getting cleared on SRX according to hold-interval configured.

EDL hold-interval gets started as soon as SRX fails to refresh any existing external dynamic list (except HTTP 405 response code) which means if the hold-interval is configured as 24 hours, EDL should get cleared after that if the refresh fails but if there is any configuration commit done on the SRX during this time, hold-interval timer will be refreshed and counter will restart and due to this SRX will hold the EDL for 24 hours after the last commit was performed. This is an expected behaviour by design.

If needed you can clear the EDL manually using the below given command:

>clear security dynamic-address (feed name)