Question on PMR massacre

I'm monitoring a cyclic signal on PMR446: digital "creek" sounds (like crackles) alternating between mid and high tones, with a fixed pattern. Sequence: mid creek → high creek → ~25s pause → ~15s communication → rapid alternating bursts → long mid creek → short pause → single high creek → repeats. No voice or Roger beep. After long consoulting with ChatGPT It Seems like a device-to-device exchange. Possible causes: digital weather station, alarm system, DMR beacon. No SDR available, just analyzing by ear. Any ideas what this could be?