If the fix is introduced in Junos version 18.2R3-S3 it will be ported to the subsequent releases. It seems like you are already on 18.2R3-S4 which should contain the fix but it isn't. I think it is a Regression issue.
As fellow community members said, try to upgrade the Junos to 18.4R3 and check the behaviour.
BTW, the Juniper Software Download page contains the 18.2R3-S3. PFB, the snippet of the version from the download page.