Hotbar changing on its own, adding melding actions in place of melee actions?

This has now happened to me three times on the same character, two different classes (Gladiator and Pugilist). Suddenly, without making any changes, hotbar 2 automatically removes three of my set actions, replacing them with three copies of the materia melding action. This seems to occur during an instanced class quest. I am not certain that the instanced quest is the cause, but it is the only time I have noticed this bug happening.

I don't typically set materia melding at all, and certainly not on a melee class. This has happened with my hotbar unlocked and also when it has been locked. I wasn't trying to make any changes to my hotbars at the time, nor was I in the middle of doing anything at all with materia.

The images show me turning in the completed quests in question and noticing that my action bars had been changed.

http://i.imgur.com/idt61XMl.jpg

http://i.imgur.com/KtS9v5pl.jpg

ISP: Xfinity Type: Cable
Date/Time when issue occurred: uncertain, NA server, EST Frequency: happened three times
Character: Deminia Brellenwind, Hyur F, Sargatanas, Gladiator (mid 20s, level synched) and Pugilist (50 but level synched), areas were first two times in Highbridge area of Thanalan, third time near Coffer & Coffin area of Thanalan
Solo
Not sure of NPC names/Monsters - several within instanced class quest

I've had this happen to me, always taking the 2nd and 3rd from the right slots of the second bar. I've never actively observed it, just noticing when it has replaced potion or "use limit break". Very weird.

This has been happening to me to! Always thought it was just me.

This happens every time I learn a new skill with any class. I thought it was because I swapped all the shared hotbars with the non shared ones. Assumed it was defaulting to the original setup. Doesn't explain why the melding Icon always erases one of my buttons. I have it set on my ltw class but no other yet its always there.

Yeyyyyy not along come on this problem SE take a look pleaseeeee Now if in order to fix that glitch will take 10 hour maint jp sever and 15 hours us eu server then get busy on now don't forget to add extra mobs that drop fleeces while y'all at it

The same problem happened again after completing another level synched instanced class quest on my Pugilist, all of the information is the same as above except obviously the date/time (a few minutes ago). I re-learned an ability (Demolish) during this quest (Return of the Holyfist). Here is yet another screenshot showing my same exact action bars replaced with 3 duplicate materia melding actions:

http://i.imgur.com/alynkBAl.jpg