If you have the ability to try swap it with another to see if it solves it, then yes that would be the easiest route.
Is the tube original to the Romy or is it possibly a replacement that came from another nationality?
I haven't owned one, but the parts I have seen available (which isn't often) seemed more robust, therefore it is possible that they used different machining processes and may have different tolerances. I haven't seen many folks with Romanians that they have done anything to, they more often are in the hands of collectors rather than tinkerers. Which, aside from their low importation numbers affects how many parts you see in the wild. I don't believe I have ever seen a Romanian gas tube for sale.
If there is a LOT of wiggle at that fitting, you might be able to 'shim' it with some metal tape that can handle the heat...not that I recommend that, but I might be tempted to try it in your shoes. Is the overall length of the tube correct with no forward and backward slippage? If it is there, you might be able to wrap a paper clip or wire (neatly) around the gas block fitting to 'lengthen' the tube at the fitting...but that would also be a LOT of wiggle room....and is a pretty crappy fix. Either of those ideas might be good for troubleshooting and making sure that is where the problem lies before buying a new tube. I wouldn't use them long term.
A machinist or plumber might know how to 'crimp' down on the tube to get it a little tighter at the fitting, as it shouldn't be much...since I am neither, it might not be possible... but if retaining the original tube is critical, it might be an option. I suppose it comes down to how much you value it being all original, if it is.