Great, there should not be any issues with old versions of Bluetooth or drivers. Here's the instructions from the WiiM manual (but it may have changed...)
https://faq.wiimhome.com/support/solutions/articles/72000614371-wiim-pro-plus-user-manualWIIM PRO USER MANUAL VERSION 1.8 8/19/23
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12. STREAM AUDIO TO WIIM PRO WITH BLUETOOTH
Bluetooth wireless technology lets you stream music from mobile devices such as
smartphones, tablets, TV, and laptop computers. Before streaming music from a device,
you must pair your mobile device to the WiiM Pro. You can put the WiiM Pro into the pairing
mode by pressing and holding the volume '+' and '-‘ buttons together for 2 seconds.
Bluetooth supports A2DP and AVRCP profiles, and both SBC and AAC codecs are
supported.
Do you know you can use AirPlay for your Macbook to communicate with the WiiM?
If you are still having problems, WiiM has a great community forum to pursue answers from the community.
https://forum.wiimhome.com/