makeWebRequest() returns Error -300 on Instinct 2S

I have a watchfae where a background makeWebRequest() returns Error -300 NETWORK_REQUEST_TIMED_OUT on Instinct 2S standard edition (not Surf edition) when connected to an Acer tablet with Android 7.0. Garmin Connect sync to the watch from the tablet works fine. The Minutecast app on the watch , which also uses communication works fine.

Garmin documentation seems to suggest that Android 7.0 should be OK, except for certain tablets that they list.

Garmin Connect App Compatibility Requirements | Garmin Customer Support

Trying the same thing with a smartphone with a more recent version of Android, there is no problem both with a cellular and wi-fi connection.

First, what is the cause of error -300?

Second, are there any suggested workarounds or solutions?

_psx_ over 4 years ago

Connect syncs because you run it in foreground. The problem with webReq is that tablet can be in sleep mode and watch can't connect to the Connect,

Show something on watch screen when req is pending than go to tablet and press sync in Connect and probably webReq will run well.

Solution is finding settings in tablet to allow some application runs even tablet is in sleep mode,

trudelta over 4 years ago in reply to _psx_

My user reported that it looks like that worked. Thanks.

UPDATE: I take that back. Error -300 is still occurring even after setting Garmin Connect to run in the foreground, and set to be not battery-optimized, there is no screen saving enabled, no sleep enabled.