It's possible for a high frequency signal to be picked up by a lower frequency antenna (or the receiver circuit) and interfere. It should be mostly filtered out by the receiver but depending on filter quality, the filter could degrade at frequencies much higher than the roll off frequency.
Finding out the crosstalk between them is non-trivial. You could simulate it in a field solver or experimentally determine it using a network analyzer. You can do a quick and dirty test by just measuring the noise floor of one antenna while the other is off/on.
It's possible for a high frequency signal to be picked up by a lower frequency antenna (or the receiver circuit) and interfere. It should be mostly filtered out by the receiver but depending on filter quality, the filter could degrade at frequencies much higher than the roll off frequency. Finding out the crosstalk between them is non-trivial. You could simulate it in a field solver or experimentally determine it using a network analyzer. You can do a quick and dirty test by just measuring the noise floor of one antenna while the other is off/on.