From an Italian Ministry of Education, Universities and Research paper, entitled “On the anomalous secular increase of the eccentricity of the orbit of the Moon” (download as pdf)

A recent analysis of a Lunar Laser Ranging (LLR) data record spanning 38.7 yr revealed an anomalous increase of the eccentricity e of the lunar orbit amounting to e˙meas = (9 ± 3) × 10−12 yr−1.  The present-day models of the dissipative phenomena occurring in the interiors of both the Earth and the Moon are not able to explain it.

Thus, the issue of finding a satisfactorily explanation for the anomalous behaviour of the Moon’s eccentricity remains open.

A promising candidate for explaining the anomalous increase of the lunar eccentricity may be, at least in
principle, a trans-Plutonian massive body of planetary size located in the remote peripheries of the solar system.

Uhm.. Ok.