HI Filip its most likely a congestion issue, also known as utilization issue... simply put too many people trying to do too much on the network in the area, has been an issue cropping up recently with the stay at home message.
I'm going to post a link and instructions to setup a Broadband Quality Monitor, once you have this setup come back and share a live link so we can see whats happening and when and we'll be able to give some more definitive information.
Connect to the hub by clicking on this link http://192.168.0.1/ That should pull up the log in page for the hub. But don't log in, just click on the link "Check router status" That'll bring up a window with five tabs. Open the Downstream tab. Select all the text (Ctrl-A if using a keyboard), copy it (Ctrl-C), then paste it (Ctrl-V) into a reply here. Post that, do the same for the Upstream and Network log. You'll get an error message when you post the Network log, just click on "post" a second time.
Then we can check for any obvious problems with power, noise or error counts.
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