TGIF.Network

There are a few places where you can enter your DMR ID in Pi-Star.  My guess is that you're trying to enter the extra digits under the "General Configuration" area.

Instead,  try entering your base DMR ID in that field and then using the drop down to select a unique suffix under the DMR ESSID in "DMR Configuration.

If using a single DMR Master, you'll only have one place to do that.  If using DMRGateway, then you could have several places to select different suffixes for individual networks.

I will try the drop down for the 3 hotspots I have.   Once I do that would it be safe to have all 3 running at the same
time even if more than one would be on the same server?

Absolutely! That's precisely what it's for: To individualize each hotspot so that it appears as a unique device when you have multiple hotspots connected to the same server.

As proof: I currently have four devices connected to TGIF at the same time.  The very first hotspot I purchased (A Jumbospot)  is connected with my straight DMR ID with no suffix.  Later, I purchased a TGIF spot from Robert, K4WZV, and designated that with the drop down as 05.  Then, a few months ago, I put two dvswitch servers online with 99 and 98 suffixes.

All four run 24x7, all play nice with the server, and all can be set to the same talkgroup or different ones.