I’d definitely try a PCTV 292e (or 290e) if you can get one as I know these definitely should work. I’ve since seen mixed reports of the WinTV one saying that some driver modifications have to be done to get it to be recognised so that can be more hit and miss. The only driver you should need for a pctv 292e would be the ct2-dvb-usb-pctv292e one. It should then work after rebooting the receiver without any further modification. Your USB extender cable should be fine, I’ve used similar for the same reason of there not being much space to plug a tuner stick in directly.
Otherwise there’s a couple of instructions you’ll need to do via the command line by the look of it to get the WinTV stick working.
Not sure regarding the scanning, it might be worth factory resetting the box from the menu to start afresh! That might fix some unknown problems. If you go into the tuning menu and select signal finder you should be able to scroll through the transponders and see if it’s picking up a signal on them (it’ll show you the signal meter and a tick box if they lock). Are you getting Hotbird reception on your old receiver?
The only other thing to check is to be careful you’re plugging the satellite cable into the correct connector on the back of the ZGemma. Sometimes on these kinds of boxes the sockets are the opposite way round (for tuner A and Tuner B ) to what you’d expect to match up with what’s in the menus, so if you’re setting up Tuner A for Hotbird, try the scan with the cable connected to each socket in turn.
I have read through various threads from various forums and I see a pattern: A lot of people have had issues getting various Zgemma receivers to search for anything, getting 0% signal strength and 0 channels found, like me. I sorted out the satellite on the roof and it's still happening. The posters on these forums typically were able to switch to another box and found that they had no issues on the other box, as I could (before I returned them). People kept insisting it couldn't be the box in these posts, above all talking about cutting the coax properly etc. I have tried re-cutting it endlessly and have filled my sofa with little foil fragments from the cable.
I don't know what Zgemma's reputation is and I haven't done an equivalent sort of in-depth search for issues with e.g. Edision, so I don't want to make any categorical judgement. Nonetheless, having experienced these issues and seeing that plenty of others have been up and down ladders over the years for the exact same reason, often without ever solving it, does make me wary.
It does seem that in Italy they still sell the Edision Piccollo 3 in 1 (what I had) with a Tivusat Gold and no CAM. I am certainly missing how simple it was with my Edision. If there is a way to get it to work with the Gold card without CAM, I would be very tempted to do that. So far I can only find bundles sold in Italy, however:
Edision Piccollo S2+T2/C H.265 Combo con Tessera Tivusat HD Gold
I'm still open to other possibilities. The Zgemma is just looking hopeless to be honest. I've tried reflashing and all sorts and it's just not going well. As I say, I can see many others have been in the same situation over the years.
Edit: Found one on eBay but no shipment to my address:
Decoder Tivusat Con Tessera Inclusa Satellitare Edision Piccollo Compatibile New | eBay
Looks like they're the only two bundle options...
This one also makes the claim that it is compatible (again no export):
Decoder Edision Piccollo Satellitare Digitale Terrestre Legge Tessera Tivusat | eBay
A while ago, I even joined an Italian satellite forum to try and sort it out (I don't speak Italian really at all so I was relying on Google), and somebody was claiming it was possible with some firmware but I was struggling to follow the post he directed me to or something. I don't remember:
Edision Piccolo 3in1, Tivùsat senza smart CAM
This one makes the claim it's compatible:
DECODER COMBO HD S2 + T2 HEVC SAT E TERRESTRE LEGGE TIVUSAT SVIZZERA SKY-DVBT2 PICCOLLO EDISION
And it's exported! So I guess I'll take a punt. They say that they set up all the channels before shipping (presumably I'll have to change them, but I'm used to that on Edision). But hopefully that means that they also do some software magic to get the Tivusat working on it. The Italian forum post also seemed to suggest it was possible. We'll see