When will the problem be resolved? Thanks.

Same problem in ru.wikisource. When trying to create a page in a page namespace, you have to wait a very long time for this intake-analytics.wikimedia.org to finish. Impossible to work.

BTW, both unable groups (Autoreview and Reviewers) are shown in https://ru.wikisource.org/wiki/Special:Statistics (red links)
In the same time, active groups Importers and Transwiki importers are not shown in https://ru.wikisource.org/wiki/Special:Statistics

In T224355#5212764, @Tpt wrote:

Has the first page of the PDF a smaller size orresolution than the other ones?

Yes.
This PDF: the first page 347x524 (22,4 kB), others about 377x529 (42,3 kB)
This PDF: the first page 163x253 (2,49 kB), others about 166x255 (3,90 kB)
Title page usually has smaller size, because there's not so many text.

In T224355#5212731, @Reedy wrote:

Are they worse on the original (in which case, there is almost nothing we can do about this)? Or just in the thumbnails being displayed?

They are worse in the thumbnails.

Special:ListUsers/reviewer has been blanked.
Yes, we want to really remove reviewer itself as separated user group (same case as T202139)

In T183133#3845490, @Ankry wrote:

The incorrect thumbnails belonged to the previous version of this file.
After purging the file on Commons few times the old thumbnails seem to disappear (at least I can find none). Local browser cache refreshment (F5) may still be required.

Russian Wikisource: same problem.