ldd -r /usr/lib/upower/upowerd
	linux-vdso.so.1 (0x00007ffe39540000)
	libupower-glib.so.3 => /usr/lib/x86_64-linux-gnu/libupower-glib.so.3 (0x00007ffbaca7e000)
	libgio-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0 (0x00007ffbac89d000)
	libusb-1.0.so.0 => /lib/x86_64-linux-gnu/libusb-1.0.so.0 (0x00007ffbac881000)
	libgudev-1.0.so.0 => /usr/lib/x86_64-linux-gnu/libgudev-1.0.so.0 (0x00007ffbac874000)
	libgobject-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0 (0x00007ffbac814000)
	libglib-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007ffbac6eb000)
	libimobiledevice.so.6 => /usr/local/lib/libimobiledevice.so.6 (0x00007ffbac6c1000)
	libplist.so.3 => /usr/lib/x86_64-linux-gnu/libplist.so.3 (0x00007ffbac6b0000)
	libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007ffbac68d000)
	libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007ffbac49b000)
	libgmodule-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgmodule-2.0.so.0 (0x00007ffbac495000)
	libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007ffbac479000)
	libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007ffbac471000)
	libmount.so.1 => /lib/x86_64-linux-gnu/libmount.so.1 (0x00007ffbac411000)
	libselinux.so.1 => /lib/x86_64-linux-gnu/libselinux.so.1 (0x00007ffbac3e6000)
	libresolv.so.2 => /lib/x86_64-linux-gnu/libresolv.so.2 (0x00007ffbac3ca000)
	libudev.so.1 => /lib/x86_64-linux-gnu/libudev.so.1 (0x00007ffbac39e000)
	libffi.so.7 => /usr/lib/x86_64-linux-gnu/libffi.so.7 (0x00007ffbac392000)
	libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007ffbac31d000)
	libssl.so.1.1 => /usr/lib/x86_64-linux-gnu/libssl.so.1.1 (0x00007ffbac28a000)
	libcrypto.so.1.1 => /usr/lib/x86_64-linux-gnu/libcrypto.so.1.1 (0x00007ffbabfb4000)
	/lib64/ld-linux-x86-64.so.2 (0x00007ffbacb1c000)
	libusbmuxd.so.4 => not found
	libblkid.so.1 => /lib/x86_64-linux-gnu/libblkid.so.1 (0x00007ffbabf5d000)
	libpcre2-8.so.0 => /usr/lib/x86_64-linux-gnu/libpcre2-8.so.0 (0x00007ffbabecb000)
undefined symbol: usbmuxd_connect	(/usr/local/lib/libimobiledevice.so.6)
undefined symbol: usbmuxd_send	(/usr/local/lib/libimobiledevice.so.6)
undefined symbol: usbmuxd_unsubscribe	(/usr/local/lib/libimobiledevice.so.6)
undefined symbol: usbmuxd_delete_pair_record	(/usr/local/lib/libimobiledevice.so.6)
undefined symbol: usbmuxd_subscribe	(/usr/local/lib/libimobiledevice.so.6)
undefined symbol: usbmuxd_read_buid	(/usr/local/lib/libimobiledevice.so.6)
undefined symbol: usbmuxd_disconnect	(/usr/local/lib/libimobiledevice.so.6)
undefined symbol: usbmuxd_recv	(/usr/local/lib/libimobiledevice.so.6)
undefined symbol: usbmuxd_device_list_free	(/usr/local/lib/libimobiledevice.so.6)
undefined symbol: usbmuxd_recv_timeout	(/usr/local/lib/libimobiledevice.so.6)
undefined symbol: usbmuxd_save_pair_record_with_device_id	(/usr/local/lib/libimobiledevice.so.6)
undefined symbol: usbmuxd_get_device_by_udid	(/usr/local/lib/libimobiledevice.so.6)
undefined symbol: usbmuxd_get_device_list	(/usr/local/lib/libimobiledevice.so.6)
undefined symbol: usbmuxd_read_pair_record	(/usr/local/lib/libimobiledevice.so.6)





======================
I should probably also mention that I've tried to reinstall libusbmuxd (sudo apt install libusbmuxd6 --reinstall), but it did not change anything. I tried the suggestion of symlinking libusbmuxd.so.6.0.0 to libusbmuxd.so.4 (afterwards removed the link, so the output above is correct), which does appear to mitigate the said problems.