Opening Edge or internet Explorer while Hoster is playing generally does cause a stutter. Best practice is to start edge and leave minimised on taskbar till needed. Also if you have edge set to open on microsoft default home page it loads lots of news flashes etc.
best to set it to open on a specific page without a lot of clutter like
https://www.google.co.uk/
You can do that various ways. Example on edge click the 3 dots top right of browser and select settings from list. Then choose (on start up) Then (choose Specific Page) then where it shows the existing home page select the dots again at the right and choose edit then type or paste the above google address or an address of your choosing.
Settings in Hoster that can help:
Tools settings general tab make sure the box is ticked for (use MTU Hoster power scheme)
Also in the Hoster audio settings play around with the two bottom boxes settings.
Graphics card settings experiment with these, Hard to point you in the right direction here but when you right click on your desktop does it show switchable graphics option ?
If so play around with those settings see if you get any improvement.