Not updating most recent version automatically

I contacted support via email. Currently awaiting a reply.

Have searched lots for solutions; Used express on 2 different PCs, turned off battery optimisation on my phone for the Connect app, looked for software updates manually to try and force it, but apparently 13.12 is the latest.

No option but to wait until they rectify it, unfortunately. I'm finding the problem on Google more the past week, so hopefully it should be fixed soon.

Same here.  Support chat just says it's a known issue.  No time to resolution.  I'm really feeling great about deciding to go with Garmin once again. /S  955 had pulse ox and hrv that Coros doesn't... I should have remembered that the software needs to work to take advantage of the hardware.

My guess is that they haven't built a delta updates path from old versions to 15.19.

Hello,
I am also having the same problem. My forerunner 955 is on version 12.29 and there is no way to update it. I contacted them by email and they gave me a possible solution, but it didn't work. In case anyone wanted to try:

Since you already connected to Garmin Express and the update did not appear, additional steps will be required, however you will not need to delete the folders to get updates in the future.

• Connect your Garmin device via USB cable
• Open File Explorer on your computer (Windows Explorer or for Mac iOS "Finder")
• Locate your device (appears as a pen drive)
• Open the Garmin folder
• Delete only the following folders below
  • NewFiles
  • RemoteSW
• Eject your device safely (as if it were a pen drive) if this option does not appear, you can eject normally.
• Power off and on your device

After performing the above procedure, connect your device again to the computer via the USB cable.
Access the following link to download it to your Garmin Express if you have not already installed it on your computer: Download Garmin Express

Click "Download for Windows" or "Download for Mac" depending on your computer's operating system and run the file by selecting "Run".

• Open Garmin Express.
• If you haven't already added it to Garmin Express, add it and log in with your Garmin Connect account.
• Click on your watch and accept the updates that the program asks for.
• Click sync. Wait for the synchronization to finish.
• Disconnect the device and accept the installation of updates on the device if any.

After performing the update, try to download Spotify again. Let me know if the update doesn't show up.

same here, brand new forerunner 955 - stuck with 13.23 - i contacted the support but no reply till now

Absolutely no idea if this may help. It was something that I had to do once before,  so putting it out here in case it helps:

Below you will see instructions to remove the update file on your watch that is not installing correctly.  Once removed, syncing with Garmin Express will send a new update file to the watch which should install correctly.  Please follow instructions exactly, as deleting some files will be permanent, as they are unrecoverable.

1. Connect your watch to your Windows computer using the provided charging cable.
2. Find your watch listed as a removable drive in File Explorer.
3. In File Explorer, double click on your watch to open it.
4. Open the folder labeled "GARMIN".
5. Look for a file named "GUPDATE.GCD".  If you see that file, delete it.  Do not delete any other files or folders.
6. Empty the Recycle Bin.
7. Install or open Garmin Express.
8. Add your device and sync.  Choose "Install All" if updates are available.
9. Sync again.
10. Remove your watch from the charging cable.
11. The watch should prompt you to "Install Now".

*If you have a Mac computer, you need to use Android File Manager to access the device drive.

There is no such file on my device

Likewise 

OK worth a try I guess., That happened to me when an update got stuck.

I am with nowster on this...Some kind of change in the way updates are detected, which is not build in in the old FW. So it cannot find the newest updates...