I do not now if my first post will arrive.
Or that post here.

But: I solved my problem via reinstall Opera. All fine for now.

I've a similar problem, but I don't think that's just Yt that causes the lagspikes and loading times.

I tried now for ~one month to get a few games of mine to function propper. (wow, my grammar today -.-)

So, now I'd get it, but than I noticed, that Yt-Videos have (seems like) randomly lagspikes and a huge loading time. In addition to that, if I want to start/stop a video and click on it, Opera needs ~2 secs to notice what I wanted to do. Even the tab close needs a few sec to get his own function. Or if I wanted to close ad's.

I had to install the K-Lite Codec Pack and this Microsoft nonsense software for the Windows Media Player, with Skype and another nonsense programs in this package. Before that, I had to install almost my complete C++ Redistribution packages new.

So, my games are working now, but my Opera does not (propper).

My System is:

• OS: Windows 10 Pro N, Version 1703, OS Build 15063.483, 64bit
• Processor: AMD FX 4100 Quadcore 3.60 GHz
• RAM: 8 Gb DDR3 RAM
• Graphics: Radeon RX 460
• Opera: Opera Version 46.0.2597.46 (PGO)

I have Avast, and no problem detected before.
All of my drivers and/or programs where complete and updated.

P.S.: I noticed, that Opera had 7-9 instances of itself in my Task Manager and if I want to look a video, my processor jumps from 7-11% to 70-80%.