Hello Charger, welcome!
From your experimentation, one could conclude it was related to a purification symptom of nascent kundalini. If it is truly debilitating or painful, then reducing practice might be in order. If it is merely uncomfortable, or something of note, then continue with practice. Symptoms come and go as the process of purification continues. No two yogis have the exact same experience.
To me it sounds like fear has driven you to practically eliminate practice which, in my humble opinion, is an overreaction. I suggest returning to a twice daily routine and test the boundries of this symptom before you give up meditation all together. If mantra meditation is too strong then go with breath meditation, or reduce the duration of each sit. Of course, honor what your Guru guides you to do; it just seems a shame to quit before you really get started[
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