I have had my internet (landline) for 4 years and whenever I played e.g. Clash royale or Fortnite, the connection is always interrupted after 15 minutes, for 45 seconds.
My internet was interrupted at Fortnite but not at Apex.
In addition, if, for example, 4 devices simultaneously watch YouTube on 1080p quality videos or Netflix, the Internet becomes very weak, but the connection is not interrupted every 15 minutes for 45 seconds, and this has been the case for 4 years.
What bandwidth in megabits per second have you booked?
Unfortunately, I don't know, but when I download something it compares very quickly with my friends, a 40gb game in 3 hours
This is extremely difficult to answer across the board.
I would ping a page like Google and see if you have ping losses.
Open Cmd on a Windows PC -> in the black window "ping 8.8.8.8 -t" (without the apostrophes "and press enter, then let it run for 15 minutes and see if you have any breaks.
Maybe your router is just old and has maken. Can you have a new one provided by your provider or you buy a new one yourself.
Or your smartphone or PC has maken.
I once wrote an article on how you can improve the Wi-Fi speed / quality yourself and listed some of the best routers under point 7. Maybe it will help you.
https://dein-technerd.de/einfache-loesungen-wenn-das-wlan-langsam-ist/
Oh, and if the router has been running for a long time, it can help to unplug it for a minute or two and then turn it on again.