I’ve had two different Roku expresses and they both have had this problem. They will both work perfectly fine for a while, then suddenly start randomly disconnecting from the internet. Now it’s to the point where it won’t connect at all, even after I reset my router and the device. I’ve tried everything I could find online on the topic, and nothing has worked with either device. I’m definitely not purchasing another Roku if this is going to happen a third time.
Whether or not you buy another Roku is irrelevant.
Are you using the 2.4 ghz band from your Router?
Do you have many other devices. cell phones, laptops or whatever connected via wifi?
Have you tested the strength of the signal to your Roku?
You could just as easily need a stronger Router.
How are you powering your Roku -- via a USB port on TV or via adaptor plugged into house power? Many TV USB ports do not deliver enough current to reliably power a Roku.
I’m starting to think the usb is the only possible issue. I’ve done everything possible with the router, it’s just not that. Do you know if there’s anyway I can buy a wall adapter anywhere? I was given this second Roku secondhand and they didn’t have it anymore
If you have a USB adapter around from another USB-powered device you can use that. Just be sure the fine print on it says its 5 volt output is at least 1 amp. If you don't have a suitable adapter handy you should be able to find one at all manner of local stores like Target, Walmart, Dollar stores, drug stores, etc.