Holden Jackaroo

Good evening!

So, I need a bit of troubleshooting advice!

I recently bought a Jackaroo and the car runs like a dream! Yesterday, it developed an issue. I'd like to try to fix it myself before paying an auto elec a fortune for something that may be simple. I'll keep it brief!

My keyless entry sets off the car alarm. I can lock my car with the remote, and open it straight away with the remote, and it's fine. If it's locked for more than 2 minutes, unlocking it (with the remote) sets off the alarm. Every time. I have 2 remotes, and have replaced the batteries in them, and it's still doing it. I have also replaced the car battery today, and it's still doing it. I even replaced the anti-theft relay, and it's still doing it. It only started this yesterday, and it's doing my head in. The only thing I can do that works is remove the horn fuse so that it's quiet, but that means I don't have a working horn. I've spent hours googling this but can't find anything useful. Any advice or ideas are welcome as I'm willing to try anything I can!

I believe the remotes are aftermarket (they don't look like the ones that are meant to come with the Jackaroo) But they don't have a brand name on them, and I have browsed eBay all day and can't find any that look the same. Looking under the bonnet, there is no speaker for the alarm, so it's wired in properly as part of the car. It might even be a genuine alarm, I'm not sure. Not really sure what else to try, it has me stumped.

Thanks in advance :)