Please configure your unit and tracker on such settings that were until 23.06.2020, since it worked successfully and please use the IP format instead of the DNS server format:
Server Host - 126.96.36.199
You can see in the logs for that day in the Toolbox (unit menu - Tools - Toolbox - section with logs at the top). That your tracker disconnected and no longer connected.
As an option, please try to check the SIM card or chip of the tracker, in particular, check whether the data transfer limits not exceeded (this sometimes happens with users), and also try to check the operation of the tracker itself (request information directly from it, for example, using an SMS command).