I have a Galaxy Watch Active 2 and version 2.0.0 for Galaxy Watch Designer.
I just can’t seem to connect my watch (I used the 40mm and 44mm). Followed all instructions and used sdboverbt as an alternative and tried using my phone as a hotspot to no avail.
I use a macbook by the way. Not sure if this is an issue nowadays. I can’t use windows since mine is very old.
We are seeing an extremely lot of problems with users trying to connect to Mac Catalina. It has to do with the RSA encryption key not showing long enough to allow it.
Some users said that having a preinstalled watch face showing allows it.
If that doesn’t work for you you will need the sdb.exe tool from Tizen Studio. (apparently the one included in GWS does not work). If you don’t want to do all the work of installing Tizen Studio open a support request and ask for them for it to connect to Catalina. Even then it may take a few attempts to connect.
Once you accept the RSA encryption key you should be good to go on GWS as well.
Ron
Samsung Developer Program
Thank you so much for your response! I was relieved that I’m not the only one who’s having this issue. I’ll try your suggestions.
Hey Ron thank you so much, I was able to connect my watch and finally tested my first watch face!
All it took was the sdb tool from Tizen Studio! 
Hello,
Can pls. FURTHER elaborate how you able to get the sdb tool and GWD to work? I was able to connect then to the old GWD but because of certain circumstances, wasn’t able to create watchfaces. Coming back recently, there’s already an update from GWD to GWS 2.0 ,and same as what you mentioned. I cannot connect my phone to GWS anymore…
I explained this in detail in your topic. Bottom line is when all else fails contact tech support they should be able to just send you the tool and not require you to download the entire SDK.
Ron
Samsung Developer Program
I’m having the same problem in connecting to my watch.
I can’t send a message to Tech Support because that link fails on the “Product Information” area. I can’t select anything there so I can’t submit the request for the sdb.exe
I wish this system of connecting to a watch was easier!
Hi Tony,
I apologize this was my mistake I posted the wrong support link earlier samsung.com not developer.samsung.com
I’ll see if I can upload the sdb tool here too.
Ron
Samsung Developer Program
The issue is that privacy regulations were changed in 2018/2019 and part of that is to encrypt data transferred to and from your device. If you don’t acknowledge the encryption key quickly it is seen as a hack and is never shown again. for some reasons it is especially difficult to notice this in time from Macs running Catalina.
If you are running Windows it is easier to resolve. If none of the hints here helped let me know your OS and other relevant information.
Ron
Samsung Developer Program
I was not able to connect my watch either even through bluetooth, so what i did was downgraded my Galaxy Watch Studio to 1.8.1 now all is fine, so it is the problem of new Update.
I downgraded too for 1.8.1. Managed to connect GWD to my watch but halfway through, an error appears. Pls. see screenshot below.
Thanks 
I don’t know of any issue with the update, but I do see more reports of this with GWS 2.0 than the last few updates. I suspect if you go back to GWS 2 it would work just fine with that now. Once the RSA Key is accepted and is connected it just works. However, I don’t blame you if you don’t want to try.
Ron
Samsung Developer Program
Well i was on 1.8.1 and my watch had no connection issues at all then i updated it to 2.0 and started showing me issues of connections from both WiFi and Bluetooth. Not connecting with wifi is a common issue for me but with bluetooth i never had any issue but on GWS 2.0 it was saying me an error like can’t be transfer which was quite annoying that is why i went back to 1.8.1. and now i wont go back to 2.0 as i know i will face same issues i am waiting for 2.0.1 and hoping to see such bugs might get fixed.