I think tomorrow I'll have time to do new batches of tests with Youtube app on multiple devices to try to reproduce a deadlock.
It's not abnormal, if there is no new address to block, you will not have new entry, Just a line like this (every 10 minutes) : [Sat 20 Apr 23:28:24 BST 2019] ads-catcher-blacklister
First time it ran, it completely blocked all videos from loading. Pi-hole was showing that all videos were being blocked via the blacklist, and this is on both Google Chrome and using the YouTube app on a Roku device. Once I removed the googlevideo domains from the blacklist, the videos worked again. The workaround isn't working, re-launching the video several times doesn't change anything.
I did lot of tests yesterday, I had problem with one video on a smartphone :
youtube app used 5 different addresses for one video
blacklister added blacklist addresses while unlocker removed them from the blacklist
history list of the unlocker was erased too quickly
unlocker is to slow when lot of requests are made (youtube and others)
I did changes (not pushed for the moment), I'll try to see If I can reproduce this situation (really not easy on my side).
Yes, as planet said, you can uninstall ads-catcher and remove youtube addresses for the blacklist file (pihole interface or directly in the file /etc/pihole/blacklist.txt)
Would you be able to test it on the YouTube TV app? Seems to be deployed quite similarly on Smart TVs, Roku devices, Gaming Consoles, etc.
I also have slow/bad internet here (3 megabit download speed) which may also play a role. But I noticed the TV app using the same googlevideo domains for multiple videos, so when blacklisting the domains, the TV app and website on my laptop had a lot of trouble loading videos.
Yes, two ways with a Desktop GUI :
1- if you have a default application to manage deb files on your system, you can launch it by doing a double click or right click > open
2- you can launch a terminal from the menu