It might be out of range. Bring it in close for testing. Then slowly test placing it where you want it to go. By slowly I mean a few feet at a time, and waiting 5 minutes before testing the next further out location.
Also when you replace the batteries on the WH32 it begins to send out using a new sensor ID. There is no need to factory reset the GW1000 when changing the batteries on the WH32. All you need to do is use the WS View app and then go to More / Sensors ID. There you click on the Re-register button and it should find the new ID for the WH32. Do that close by to the GW1000. Then start the moving away testing.
Realize that the signal indicator bars are not live and they don't represent signal strength. The bars indicate reception of data within the last broadcast interim.
See here for more details on signal bars:
https://www.wxforum.net/index.php?topic=36486.msg374628#msg374628Yes this linked post discusses the WS-2000 and signal bars...but it is the same for the GW1000.