Spring Scheduler with cron expression stopped working

There's an issue which I would like to discuss . On 7 Nov 2021 , at 12:59:58 AM EST -4UTC , the Spring schedulers which were configured using XML and cron expression stopped working and resumed only after 1:00:00 AM -5UTC without any intervention. Although , the schedulers configured with fixed-rate were working fine throughout. The server timings on which the application was hosted was in EST time zone. So any idea as to why the cron schedulers stopped working at the above given time even though the Day light saving happens at 01:59AM-4UTC. Or this whole situation is not related to DST?