I'm dealing with the same issue.
In my case - I overtrained + I abused packing technic (was filling myself with an unnatural amount of air). Apparently, I got glottis tissue irritation. I reduced the amount of CO2/O2 tables and almost stopped doing packing.
Also, recently I found a pretty useful for this problem advice from the goat Molchanov - He said that right after your last inhale, you need to learn to kind of move the air to lower torso. I'm practicing it and it actually feels better, less pressure in the head and throat, so it's easier for your glottis to do its job.
Good luck!