Does your router have a firewall?
If yes, try to turn it off first to see if it changes anything. If it doesn't, it's not, if it does, you'll have to configure it.
Have you done speed tests on the SLR or DEOVR application?
You say it's not coming from your provider, but without giving absolutely no info (which provider, your type/speed (up/down) of connection, we'll have to take your word for it.
Does this problem occur throughout the day, or only during certain time slots?
Anyway, there is a lot of information to give, but you don't give anything.
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