Yes, ultra wideband signals may interfere with other signals. Again, the extent to which they do this depends on the power and frequency of the UWB signal, and the power and signal of the other signal with which they may potentially interfere.
Therefore, to minimize interference, UWB signals are usually used within a specific frequency band that are allocated to UWB alone.
This goes a long way to ensure that no other signal takes that space therefore causing interruption. Additionally, UWB technology also makes use of techniques like spread spectrum and frequency hopping for eliminating interference.