And I think this is important; might make all the difference:
Meyer lemon trees need 8–12 hours of bright light each day to grow properly and produce fruit. Place your tree near a south- or southwest-facing window to maximize natural sunlight. If sunlight is insufficient, supplement with a full-spectrum grow light to simulate daylight. This is especially helpful during shorter winter months.
I had a Meyer Lemon once, and I put it in front of a big full-length window. But though that seemed adequate to me, it was not enough to keep the plant happy.