Earlier this month, Microsoft released the Windows 10 May 2019 Update to the general public in waves, and for the most part, things have gone relatively smoothly (at least if you aren’t running RAID on a Ryzen-based system). Microsoft allowed an extra month for testing with Windows Insiders and has taken additional steps to ensure that the May 2019 Update wouldn't be as disastrous as the preceding October 2018 Update.
With that being said, some users have still encountered some nagging issues; namely with regards to Bluetooth and Wi-Fi connectivity. Microsoft has updated its "Known Issues" page for Windows 10 to confirm that it has discovered an incompatibly problems with drivers for certain Bluetooth radios manufactured by Realtek and Qualcomm.
Once Microsoft identified the problem, it began to pause the update for systems that have the targeted hardware installed. For those having issues, Microsoft advises that you manually install updated Bluetooth drivers for these systems. If you have a Realtek Bluetooth controller, Microsoft recommends that you install driver version 1.5.1011.0 or newer. For Qualcomm controllers, you will need to install driver version 10.0.1.11 or newer.
As for the Wi-Fi issues, this seems limited to systems that are using an outdated Qualcomm driver. Microsoft says that the incompatibility is causing "some older computers may experience loss of Wi-Fi connectivity." As with the Bluetooth issue, Microsoft is now pausing the May 2019 Update from installing on these systems. As a workaround, Microsoft suggests that you obtain a new driver direct from Qualcomm or your PC manufacturer.
In both cases, Microsoft is working with the hardware vendors to push updated drivers through Windows Update. Once that happens, you can expect for the upgrade block to be lifted. You can read more about the issues affecting Realtek and Qualcomm hardware in the Windows 10 May 2019 Update right here.