First i add screen shot then when i look in picture i found error Invalid connect time and i reasearch and found this in my GTMdata.xml:

<?xml version="1.0" encoding="UTF-8" ?>
- <gtmData xmlns="http://www.garmin.com/xmlschemas/GtmData/v1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.garmin.com/xmlschemas/GtmData/v1 http://www.garmin.com/xmlschemas/GtmDatav1.xsd">
- <unit>
<unitId>3758365022</unitId>
<lastConnected>2020-01-01T00:00:10Z</lastConnected>
</unit>

Then i change 2020-01-01T00:00:10Z to 2011-01-01T00:00:10Z and Invalid connect time desapire

I replace today my old GTM36 for new GTM36 in store but again also new GTM wont work.On this GTM36 is original subscription but i stil have SYS 2.10 and BB 2.10 but you have SYS 2.20 and BB 2.10
So if you tell me how can i upgrade GTM FW i will try.