UWB as rescue from the jammer.

I am using Hope RF RFM12B modules (868 MHz band, 9600 bps) to transmit motion sensors signals over a short distance, 16 times per second, several bytes of data at a time, unidirectional. But someone is intentionally interfering with my transmission.
Distance from my transmitter to my receiver - approximately 25 feet. Distance from the jammer to my receiver - approximately 10 feet (through the ceiling - one floor above). Bringing the receiver close to the transmitter - to 2 inches distance - does not help (when jammer is active).
I started using 64 channel hopping (it changes 4 times per second). They coped with that too after month.
I need some different, better, reliable solution.
Is the data transmission (from motion sensors - minimum amount of data) via the UWB immune to intentional interference?
For example, if an intruder uses the same UWB transmitter as mine, will my received data remain error-free?
Which UWB module is right for my needs?
Thank you.

Nothing is completely immune to jamming. UWB can be made to be very resilient to narrow band jammers, a notch filter for the jamming frequency will do the job most of the time. If they are sweeping a frequency range you can make this a very wide filter. With >500MHz of bandwidth you can filter out a fair range and still get enough signal.

If you are using an IEEE compatible UWB system like decawave then another similar system running a high duty cycle will still cause interference. If I set one system running flat out and then try to use another independent system with the same radio settings in the next room it will have issues.
But they have to know that you are using UWB to start with in order to jam it. Unless you know what to look for a low duty cycle UWB system is hard to detect.

In terms of using UWB for data transfer you would need appropriate firmware on the radios, the off the shelf system that is supplied is designed for position calculation not data transfer. However creating a simple point to point link based on the code examples should be fairly straightforward.