If you are one One UI 6.....I believe you'll have "Modes and Routines" in your settings..
Go there and this simple routine of "If Youtube or Instagram app opened and Wifi is disconnected.....Then change network provider to 5G/LTE/3G/2G".
And set default Network to LTE/3G/2G.
This setting will save you more battery..
Try Once and Let me know your experience.
