BTW I just successfully downgraded my firmware to Tizen 2.3.2.3
Here are the instructions (careful not to brick your device make sure you have the right firmware!!):
https://forum.xda-developers.com/gear-s3/how-to/rom-samsung-gear-s3-classic-sm-r770-t3646789
I’ll try Tizen 3.0 again when there is a stable solution.
Here also the same issue as before…watchface changes within minutes to the default watchface 
Gear S3 classic SM-R770 (none LTE)
Tizen 3.0.0.1
Tizen v. 3.0.0.1
Soft: R760XXU2CQL1
Knox 2.2.0
KTW SDK: 2.2.0
SE for Tizen 1.0.0
TIMA: 3.0.0
Batt: 40%
Storage: 1.81GB Free
Facer companion 4.2.5.5
Happend within minutes in remote-connection mode (bluetooth on watch on, BT on phone off)
Wifi Automatic/Connected
NFC On
AON mode ON
Looked promising, but back to same issues as before.
A few times now, and as before, when I flip my wrist up to activate the screen I see the Facer logo and then the “optimizing watch face” message. Still reverts to default watch face too after a few hours.
Watch rebooted and all other suggestions tried, really annoying as I love my custom face!
Would it be possible to introduce some basic logging under the triple tap menu or something to track this and narrow down the cause? Have your dev team got these watches and are they able to replicate the issues?
4.2.5_ios
Model: Non LTE
Tizen: 3.0.0.1 R760XXU2CQL1
Face: Harley - Omnitrix (Basic) - watch face for Apple Watch, Samsung Gear S3, Huawei Watch, and more - Facer
Turn on the location on the watch and the issue 3 disappear
Thanks, ill try this today and report back
This not the better solution, the battery drain very fast, but the issue #3 disappear.
This works, face hasn’t gone back to default now since. I actually briefly saw “Location” on the screen just before my watch face was shown after flipping up my wrist up which certainly shows something is going on with location.
I have an Lg watch urbane without lte. since the last upgrade watch shuffle stop working. I manually set the face and when i activate the shuffle mode on phone i.e. after one hour, face does not change. on my watch is displayed only the facer logo and “powered from facer”. so sad for this. never had this problem before. i have unistalled from phone and from watch and reinstalled. please solve it. thank you.
Failed/went to default within moments. Will keep trying.
Updated to 4.2.5 on Galaxy Gear S3 Frontier SM-R760 (Reinstalled)
Tizen v. 3.0.0.1
Soft: R760XXU2CQL1
Knox 2.2.0
KTW SDK: 2.2.0
SE for Tizen 1.0.0
TIMA: 3.0.0
RAM: 283.3
Batt: 76%
Storage: 2.80 GB Free
Try turning on Location on the watch, this seems to stop the watch reverting to the default face.
Mine hasn’t gone back since.
Hi Harley, Thanks a lot! I have applied ur solution & till now it is working fine… 
How is the battery with location turned on? Also did you try it in standalone mode?
Hi @CeeJay the battery life drains so much faster with the Location on. But I would prefer that rather than the watchface keeps on going back to default.
Just need to charge them every night now. But it’s all good.
Thanks for the tip @harley
Yesterday upgraded to 3.0.0.1 again.
I have location service turned on but in the wireless mode only.
Tried it al day yesterday and today with watch in standalone mode.
Until now no reversion to default.
Also battery drain seems to be minimal because of the network only setting.
For now this is a good temp fix until Samsung fixes Tizen.
The new version seems to be stable, 11 hours in and no issues.
Thanks Facer Team!!! 
Thank you guys for being so patient!
Note that we’re still working on a complete fix with Samsung - this is a firmware bug that we have to create workarounds for, which isn’t ideal.
Since the last update my Gear S3 no longer get updates for the following complications:
Weather icon, Weather Daily Low, Weather Daily High, Weather Current Temp, Sunrise & Sunset Times.
It still will not update the current time after turning on the screen via a button. I have disabled all auto screen on features(Bezel turn & motion) Will only turn on via a notification or button now.
I have to rotate the bezel or click the menu button then the back button to see the current time.
Also when ever I go into the Facer edit screen to change faces the screen will flicker from Facer view of current face and normal view.
Any thought on this???
I wasn’t able to grab that other watchface so I apologize I couldn’t give a neutral test. I did, however test today and saw that the latest version as of 2/10 fixed the issue. I’ve had it running for about 2 days. Haven’t tested low-battery yet but so far so good.
Thanks for responding previously!
I paid plus.
Can I use a premium theme?
You will see the message “Pay now.”
is it normalcy?