I do have a thought: a new batch with cow’s milk (also pasteurized) and see what happens. I find that raw milks don’t get thick as easily as pasteurized alternatives and my goat milk never solidified much. Even if you do not drink milk for whatever reason, consider a 24 hour culture with pasteurized, organic cow milk. If you see some progress, then I recommend trying a few more 24 hour cycles to revive your “kefies”. Cow’s milk may be favorable initially.
And of course, update me!