Vulcax will not rank up

[(NSW)RundasIceMaster]

I don’t know if anybody else has experienced this but recently, I’ve found that my Vulcax will not rank up.
 

Oddly enough, it appears to be gaining XP of some sort— occasionally, while playing with it equipped, I’ll get a “rank up” message on the UI with no weapon name or rank appearing. This is a UI bug I’ve recently experienced with another companion weapon (the Prisma Burst Laser), but it has never correlated with me gaining more or less XP than normal so I don’t think the UI bug is related to the Vulcax not ranking up properly.

I have two screenshots. My apologies for the potato-tier quality, I do not have the necessary recording equipment to get good screenshots, but hopefully these at least get the point across. First one is of the mission complete screen with the Vulcax listed as unranked. Second one shows that the unranked status extends to the upgrade screen, and also what mods I put on it.

I hope this can be resolved soon, as I am somewhat worried that this will end up messing with my mastery progress. I honestly don’t know how the Vulcax XP I earned is being treated by the game, beyond that it’s clearly not registering properly. Thank you for reading!