@PhilipL Flatpak is not just a version, it's a completely different packaging system on it's own which makes strawberry run in a sandbox environment, all features might not work and there might be restrictions such as permissions. I do not recommend it. Linux Mint 22.1 is compatible with Ubuntu 24.04 (Noble), so you can use the PPA package repository (https://launchpad.net/~jonaski/+archive/ubuntu/strawberry) to get updates. There isn't a sync with mobiles (where does it say that?), but you can manually copy or delete songs from a mobile phones supporting the MTP protocol. If you go on the the devices tab and double click to connect it, then you can go on the collection tab, right click on songs and select "Copy to device". In the the device tab you can delete songs by right clicking. There isn't any help documents.

@philipl No-one answers on this forum. Bit weird given that Strawberry is such a great piece of software.