No clue why this happened for some users, but seems resetting the network settings solves the problem.
A workaround exists to use transdroid search on recent versions:
Bad news, today I have received an email from the Play Store support:
There are many complains about the lack of dark theme in the new release in emails and in the store comments. It is totally understandable. The dark theme is in progress, and will be released in a few days, also with some adjustments on the light theme too.