Comparing a new batch against an old one. A coated tablet with no imprint is different in a way that may be nothing.
Weight and dimensions are how blank tablets get identified, and you cannot do that from a photo.
A batch number and an expiry that are almost up on a new purchase usually means the box was copied.
A smell that is wrong is a reason to look closer, not a verdict. Excipients do most of the smelling.
Imprint is the strongest signal, colour is the weakest, and the shape only narrows the manufacturer.
Country is in the details, which I know matters.
Take one to a pharmacist. Free, two minutes, correct. Everything else here is a hypothesis.
The pain score conversation is thirty seconds of my life I will never get back, every time. Side effects was my main issue with a coated tablet with no imprint too.
Sorry, probably obvious, but where do you even start with something blank?
You are not imagining it and you are not being difficult. Document it and take the document in.
Pharmacist. Two minutes.