This bug has existed for months, and is only present on specific models of mobile phone (e.g Samsung Galaxy S21 Ultra) which I've been able to confirm through extensive side-by-side testing of a Samsung Galaxy S10+ and the aforementioned S21 Ultra.
Over several weeks and game versions I've run multiple tests, which included: Factory resetting the phones / Uninstalling then Reinstalling Runescape / Playing the game with only 10% of the cache downloaded / Playing the game with a 100% downloaded and verified cache / Running the game via the Samsung Game Launcher vs. without / Any combination of in-game graphics settings that you could think of / etc. etc. etc.
In all tests the issue was present on the S21 Ultra, whilst the S10+ reliably displayed the item counts every single time.
THE ONE EXCEPTION: I've had item counts displaying on the S21 Ultra a total of two times under very specific circumstances that are not however practical as a solution due to the method. This was achieved both times by having the phone sit at the lobby (the screen shown after logging in, but before selecting a world) for an extensive period of time before joining a world. It is unclear if this was some kind of fluke but regardless it is not a feasible solution as the extensive period of time I mentioned was in the first case 2 hours whilst I was charging the phone and the second case 30 minutes and keep in mind that the item counts will again disappear the next time you reload the application.
As stated above the issue is hardware related in some way as you will experience this bug on all Samsung S21 Ultra's from my experience; Hoping this helps to narrow it down.
I've included a screenshot of what the bug looks like for reference.
Over several weeks and game versions I've run multiple tests, which included: Factory resetting the phones / Uninstalling then Reinstalling Runescape / Playing the game with only 10% of the cache downloaded / Playing the game with a 100% downloaded and verified cache / Running the game via the Samsung Game Launcher vs. without / Any combination of in-game graphics settings that you could think of / etc. etc. etc.
In all tests the issue was present on the S21 Ultra, whilst the S10+ reliably displayed the item counts every single time.
THE ONE EXCEPTION: I've had item counts displaying on the S21 Ultra a total of two times under very specific circumstances that are not however practical as a solution due to the method. This was achieved both times by having the phone sit at the lobby (the screen shown after logging in, but before selecting a world) for an extensive period of time before joining a world. It is unclear if this was some kind of fluke but regardless it is not a feasible solution as the extensive period of time I mentioned was in the first case 2 hours whilst I was charging the phone and the second case 30 minutes and keep in mind that the item counts will again disappear the next time you reload the application.
As stated above the issue is hardware related in some way as you will experience this bug on all Samsung S21 Ultra's from my experience; Hoping this helps to narrow it down.
I've included a screenshot of what the bug looks like for reference.
05-May-2021 02:23:20