In article ,
Nicolaas Vroom writes:

The article:
https://www.newscientist.com/article...ses-missing-m=
atter-has-just-been-finally-found/
claims that:
"Half the universe's missing matter has just been finally found"
implying that a lot of dark matter is not non-baryonic
but baryonic (i.e. ordinary matter)

The standard number is that much less than half of the missing matter
can be baryonic.

A article in with a different opinion:
https://www.forbes.com/sites/startsw...ing-matter-fo=
un=
d-but-doesnt-dent-dark-matter/#499df136faf7
"Missing Matter Found, But Doesn't Dent Dark Matter"

Right.

This article reads:
"The fact that about 5% of the Universe's energy is in normal matter,
27% is dark matter, and the other 68% is dark energy has been known
for nearly 20 years now,

Right.

but it remains as puzzling as ever."

Whether it's puzzling is another question, but that's the way it is.

Most(?) of this comes from studying the CMB radiation.

Yes, the CMB provides good constraints, but is also in agreement with
other tests.

The article also states:
"But light plays a major role, too. Stars shine etc so measuring the
light coming from all of them tells you how much mass there is."
The problem of course is that there is a lot of (?) baryonic matter
which does not shine.

This is also nothing new. What is new is that some of it might have
been found.

https://en.wikipedia.org/wiki/Cosmic...ave_background
We read:
"The angular scale of the first peak determines the curvature of the
universe (but not the topology of the universe). The next peak---ratio
of the odd peaks to the even peaks---determines the reduced baryon
density. The third peak can be used to get information about the
dark-matter density." I assume the non-baryonic density.

Right.

This raises a serious issue: How can these CMB peaks be trusted and be
used to make predictions when observations reveal that the ratio
baryonic versus non-baryonic matter has changed?

The only thing which has changed is the ratio of KNOWN baryonic matter
to non-baryonic matter.