(Problem reported to Apple Jul 5, 2019 but I got no answer as of Aug 1, 2019)
If you work for Apple please review FB6505912. I have sent to you system reports and Samples from the process.
I am experiencing a very strange bug on Safari. If I leave a webpage that uses websockets heavily, then sleep the system and turn it on back after a couple of minutes, the tab page keeps the CPU at 99.9% all the time, burning down my battery and CPU (it reaches 100ºC). I need to open Activity monitor and kill the page every single day.
My system is running MacOS 10.14.6 (18G84) and Safari 12.1.2 (14607.3.9).
It's a MBP 15' i7 2018 with 32Gb of RAM.
I have already cleared the NVRAM and SMC and it didn't solve my problem. I think it's a bug from Safari itself.
Thank you, it's my first post here so let me know if you need more information.