Hotdeploy did not work with the last batch of Lets Encrypt certs

I just wasted several hours trying to figure out why the certs that my scheduled task moved to hotdeploy folder do not get deployed. There was no change to any of the scheduled tasks/scripts, in years. No changes to the OF or its configuration, in months, since I upgraded to 4.8.1. The only difference was the last batch of certs, and I have no idea how different they are other than in their issue/expiry dates.
When I imported the cert/key manually, they imported without issue and showed up in the store and on IM clients.
I do not see any errors being logged that have something to do with certificates or hotdeploy.
No amount of restarting OF service (which I did not have to do previously) helped replace the certs with hotdeploy.
Never had this issue on the previous 4.6.something previous version, in several years.

As someone who uses the plugin i feel obligated to tell that there is not issue with the plugin for me.
It works perfectly. What OS are you running your Openfire on? check if your certs belong to Openfire when they arrive at the directory.

Some users of Openfire who had similar problems suggested to remove the default self signed certs. Not sure this helps also in your case.