Loading things

My iphone XR is unable to load things/keep a connection and I genuinely dont know what it is. My provider is saying my internet is fine and that its nothing with that yet despite that i find that most of my apps are unable to load or process me doing stuff on them for basically all the same things. A network/loading error. I have to either A) repeatedly do/load whatever it is on the app until it shows up or B) I restart the app and reconnect to my wifi yet even after alll of that its still the same problem i go on the next time. I tend to turn off my cellular data when at home to save data for when i go out and my phone isnt even able to keep the connection it has when i reconnect it within 8 minutes of reconnecting im down from three bars to one and stuff starts to stop loading. Its happening in multiple apps and its been going on for like a week and i honestly just want to be able to use apps for more than 10 minutes without being stuck waiting for something to load for 5. Before this on my old iphone same model i also was having a problem similar to this where i was connected to the internet but it would take forever to load things or they were just unable to load and i need to restart it