I’ve always used whatever the latest one released by Atik is, Joel. I last updated when the EFW3 came out, which was earlier this year, and have never had an issue.
The reason I’m sure this isn’t a SGP issue is that there are many posts dotted about talking about this issue outside SGP, from years ago, in other forums. I think the consensus generally is that it is a timing issue, in that more often than not, if you connect to the FW immediately it is fine, but if you power up and don’t connect straight away the problem manifests. I’ve tried it in all sorts of ways and never been able to recreate it consistently enough to be convinced this is the case, but it happens for me outside SGP also using the SX software.
From memory SX didn’t write the ASCOM driver, it was written by Bret McKeel for them, but was last updated many years ago. You would like to think they would perhaps have a fresh look now and update as necessary.
I think also that SX really intend (hope) for their devices to be used with their own software.