I haven't heard back from A+E Networks Support about this issue. They wrote to me the same night that I submitted the ticket to confirm whether the problem was with the live streams. Since then, nothing. I just sent them an email to ask for an update.
Earlier in the evening, I watched the History channel for a good half hour and didn't notice any problems with the stream. Last week, it took less than 10 minutes until I noticed something wrong. So maybe they have done something.
Hopefully, I will get an update tomorrow and will report here.
--- Edit: Here is the reply I received today:
We don't expect an immediate resolution, but please be assured that your report has been forwarded on to our engineers who will look into it further as part of their maintenance of the HISTORY and Lifetime apps and website.
Thank you,
HISTORY Support