On Zorin OS 17.3 the Bluetooth functionality is completely broken to the point it is unusable and I was forced to switch to another Linux distribution. This issue is specific to Zorin OS this does not happen with Ubuntu or any other Linux distribution and I see posts online and it appears these Bluetooth issues happened around the initial release of Zorin OS 17 and it appears the developers have been ignoring the Bluetooth issue with no fixes. I was able to fix the Bluetooth mouse not being detected issue by installing Blueman but it did not fix frequent disconnects/audio dropouts with Bluetooth speakers and headsets that only happens on the Zorin OS distribution but it does not happen on Ubuntu or any other Linux distribution. I think Zorin OS was one of the best distributions but I cannot use or recommend Zorin OS until they fix the issues with Bluetooth and their is plenty of posts to show this is a widespread issue with Zorin OS.
What do You mean in Detail with ''unusable'' and ''completely broken''? Did the Bluetooth not even run? Weren't You able to turn the Bluetooth Toggle on? Or worked the Bluetooth but Your Devices weren't detected or they were detected but they didn't get connected? Did You get any Error Messages? If yes, which one? Did You checked the Logs for Errors?
Can You name Brand and Model of the Devices? Did You checked if in the ''Additional Drivers'' Tab was a Driver offered for Your Bluetooth Card? Did You checked the Status of the Bluetooth Service in Terminal with sudo systemctl status bluetooth?
Unable to detect mouse with default setup, have to download another Bluetooth manager Blueman to uncheck hide unknown devices to see Bluetooth mouse, Bluetooth audio/speakers experiencing disconnects/audio dropouts. This only happens with Zorin OS no other Linux distribution has this issue. I am using a Dell Inspiron 15-3520. I checked the additional drivers their was none to install. This is a Zorin OS specific issue Ubuntu, Linux Mint, Elementary OS, Debian, Linux Mint LMDE 6 does not have have these issues and Bluetooth works flawlessly on those distributions of Linux. All you have to do is search on Google Zorin OS Bluetooth you will see a lot of posts of people having issues with Bluetooth on Zorin OS.
My mothers bluetooth died after an update she did maybe a week or two ago. She hasn't used her laptop - now it's busted. I'm not there to help, but i've remoted in. You cannot turn it on - it's as if the hardware isn't there.
systemctl status bluetooth shows active/running.
lshw -c network
*-network
description: Wireless interface
product: Wi-Fi 6 AX200
vendor: Intel Corporation
physical id: 0
bus info: pci@0000:01:00.0
logical name: wlp1s0
version: 1a
serial: [redacted]
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress msix bus_master cap_list ethernet physical wireless
configuration: broadcast=yes driver=iwlwifi driverversion=6.8.0-64-generic firmware=77.2df8986f.0 cc-a0-77.ucode ip=[redacted] latency=0 link=yes multicast=yes wireless=IEEE 802.11
resources: irq:73 memory:fcf00000-fcf03fff
bluetoothctl
Agent registered
[bluetooth]# show
No default controller available
[bluetooth]# list
[bluetooth]# power on
No default controller available
[bluetooth]#
So, yeah, i think there's a problem.
OK. That was weird.
Following the info from @toolman1990 - i installed Blueman. As it was her account, it required my credentials (she doesn't have sudo). Once installed, i opened it and accepted the prompt to force on bluetooth or whatever (sorry, i didn't get good text/screenshots). It didn't seem to actually work. Bluetooth didn't seem to toggle on still. So i rebooted. Upon reboot, mum logged on and after the laptop required my credentials. So i went well ok i'll do it this time, lets check Bluetooth. Nope, it didn't seem to work. So i checked rfkill (terminal) which showed Bluetooth as "unblocked". I decided to remove the Blueman software and rebooted.
Checked rfkill and still unblocked, and oh - Bluetooth is working again.
I haven't used rfkill for many years - i forgot about it tbh. But perhaps using rfkill rather than Blueman is a good way to resolve this issue if it happens to you. Rather than all the stuff above, perhaps this one simple trick will fix it? sudo rfkill unblock bluetooth
Here's a decent little guide:
Thanks for posting your experience! Bluetooth is not perfect on Linux, it works for some, not for others, and is entirely dependent on drivers in the kernal. Having to unblock Bluetooth is something I wouldn't have expected a user to have to do, after an update, strange.
I am however aware of the on/off toggle for wireless devices however.
It wasn't possible to toggle it on through normal means. Something had to force Linux to properly see it again before the UI would respond normally to the attempt to toggle it on.
For a Linux/Zorin noob who relies on Bluetooth, this would be most discouraging.
My Bluetooth has also been irrational after the latest updates. For the past week, it randomly disconnects and I must run
sudo systemctl restart bluetooth
to get it working again, each time. All other troubleshooting has failed.
I suspect a driver regression.
It happened to her again 
I fixed it by installing blueman, rebooting, removing blueman, rebooting.
Note that she can't do this - she has a limited account. I have to su - d-man to install/remove. I didn't see the systemctl restart method @Aravisian noted until just now (the day after). I'll try that without blueman next time. Hopefully that works, as i can write up a little script.
edit: oh, i did try sudo rfkill unblock bluetooth but that didn't work. It wouldn't make sense if it did, because rfkill sees bluetooth just fine.