I agree with DRG, there isn't anything new about the Leo-2 in this article. It is a general rule to never leave your tanks being hit at the sides/rear. This basic rule has been in violation in Syria for so many cases it is not even funny anymore.
Btw, here's the video showing one of the deadliest disasters the TSK suffered in the Afrin operation (and the video that the article probably used as a reference). Basically a Leo was hit in the place mentioned, it exploded violently and to top it off, it was refueled right there in the line of contact, with the end result of 7 soldiers killed. I do not think that makes Leo-2 a bad tank, at least not more than how T-72's reputation was tarnished after ODS.
https://www.youtube.com/watch?v=YafzmkvVRiI
Some other instances of other "invisible" tanks:
Saudi M1A1s hit by Houthis :
https://www.youtube.com/watch?v=B1yTb3vF35M
Iraqi M1 hit by ISIS:
https://www.youtube.com/watch?v=y5xKCzdhAC8
Tried to find if there is a video by Leclerc but I couldn't find. Basically the trend is the same: tanks that should have resisted the ATGMs mentioned did not because guess what: they were hit on the sides/rear.
Basically this can happen for two reasons: either the frontline is easily infiltrated and thus give ATGM crews good angles to use their missiles, or some isolated areas of resistance aren't properly cleared. In both cases, it is plain old poor tactics the main reason for tank losses.