You need to figure out what is causing the issue. For safe measure, I would start with an IPTV Reset. Shut down your device, go to the Donation Checker, login, click IPTV Reset, wait 15 minutes to restart your device. While you are waiting, reboot your router and modem. Also, clear the cache in your device. If things were working well before (and I'm not sure of that), your device's memory may not be at issue, especially if all channels are presenting the freezing issue.
If that doesn't do it, you need to start looking at the ISP and routing. The easiest way to address that is to try a VPN. There are free ones out there to try. This helps determine if the ISP is throttling or if there is a bottle neck in some portion of the route from the server to you.