Can you try assigning a different ringtone just incase the one chosen is naturally low to your hearing.
Usually turning up the volume by pressing the volume rocket and then on the pop up hot the 3 little dots and choose the relevant slider helps.
Also try a soft reboot by turning the phone off and on and make sure none of the speakers are clogged up with debris.
There is a diagnostic test in your Samsung Members App under GetHelp and then Diagnostics.
A Samsung Service Centre can look at the phone.
Daily Driver > Samsung Galaxy s²² Ultra 256Gb.
Samsung Gear s³ Frontier Watch.
Samsung Galaxy Watch⁴ Classic.
The advice I offer is my own and does not represent Samsung’s position.
I have no affiliation with Samsung.