After syncing data via WiFi, watches start disconnecting from the Bluetooth connection to the phone.

Four different watches doing the same thing connected to the same phone?

Yes. Oddly enough. I tried using different watches every day. And the same thing happened to them. The story goes back to August 2024, after the Garmin Connect update. After that, I tried connecting many Garmin watches to Bluetooth. And the same thing happened. I changed my phone from Samsung S21 to S24. And nothing changed. After that, I bought Fenix 8 and thought that this wouldn't happen to them. However, the same thing happened to them.

Unfortunately, Samsung Galaxy S2* phones are quite known for interferences between Wi-Fi and BT (both of them using the same 2.4 GHz band). These interferences can cause problems especially with devices using lower power (which is the case of Garmin watches). Resetting the network on the phone may help mitigating the problems, because there is a chance the BT and Wi-Fi channels get assigned slightly further away from each other, hence reducing the interferences. I recommend trying it.

It's a shame. Premium devices and they don't get along with each other. I paid about 2000.- for the s24 and the fenix 8. As a result, I suffer as if I use the cheapest and most unknown devices.

If this problem has existed since the s20 - s24 series and Garmin has already released the Fenix ​​8, and after 4 years the problem is still relevant, I think it's time for the two giants in the wearable electronics industry to help their loyal users. What is the best phone for Garmin then?

Karaban said:

What is the best phone for Garmin then?

I have no problems with my "noname" industrial Android (actually Oukitel), as well as with iPhone SE. However, if you follow my advise, and reset the network on the phone, your Samsung may cope with the interferences better too.

Most complaints on this forum come from Samsung S2* and from Pixel phone owners. Previously, Huawei used to be a huge troublemaker, but it is now a few years I did not see any complaints about Huawei here. So either it is no more a popular brand, or the issues were fixed.

Thank you. I reset the network settings on my phone several times. After a while, this problem returns. And all data and passwords for Wi-Fi and Bluetooth are erased irrevocably.

If the reset alone did not help in long-term, then there are also some other tips in the Sync / Connection Troubleshooting Guide.  Look up especially those mentioning Samsung - there are minimally 2 or 3 of them if I remember well.

Hello.

This action helped.

On some phones (namely reported on several SAMSUNG models), you may need to reset the network settings, typically under Settings » General management » Reset » Reset wifi and bluetooth. Please note you'll loose all network settings for wi-fi and Bluetooth a will have to re-do them.

All WiFi and Bluetooth data was deleted.Also all devices were deleted delayed lock samsung.Most likely, there was a conflict because I had devices there that were not compatible with this function: headphones and other smart watches, not Garmin.Everything works fine for the second day. I hope this was the reason.

I got Samsung S23 Ultra.  I have not issue with the connections at all with my Fenix 8 via BT or WiFi. My router is scheduled to reset automatically once a week.  I think you should reset your main router once in a while.