From https://www.mmsp.gov.ma/fr/actualites.aspx?id=1940 (translated)

The Morocco government decided that "[...] on the holy month of Ramadan, the
Kingdom of Morocco will return to legal time of the Kingdom (GMT) by delaying
the time by 60 minutes and this on Sunday April 19 at 03:00 in the morning In
accordance with article II of the decree n � 2.18.855 (October 26, 2018)
relating to the legal time of the Kingdom, and to the decision of the Head of
Government No. 3.25.20 (published on April 13, 2020) concerning the legal
time."

From
https://github.com/eggert/tz/commit/f9aacafa4f15be6e7ff4436164e14d8f08839ac7

>    Morocco springs forward on 2020-05-31, not 2020-05-24.
> [...]
>     Morocco's second spring-forward transition in 2020 will be May 31,
>     not May 24 as predicted earlier.
>     Adjust future-year predictions to use the first Sunday after the
>     day after Ramadan, not the first Sunday after Ramadan.

https://mm.icann.org/pipermail/tz/2020-April/028939.html

This will be reflected in an upcoming version of the time zone database.