Anyone come across these before?

Even if someone has, the chance of them coming from the same source is close to zero, therefore your question is pointless, the best thing to do is to reagent test your pill to make sure they are legit mdma and not some other drug or research chemicals being sold as mdma.

No one can tell you what is in your product, anyone can put anything they want to into pills or crystals or gels / edibles. The only way to know from home is by reagent testing, such as marquis, mecke, mandelin, simons a & b, robadope, etc, there are some sources for test kits in the "about" section of this sub or check out r/ReagentTesting for more.