Relays with low consensus weight in April-2023 in Asia

A relay operator reported that their relay consensus weight dropped in April (2023) and since then, it hasn't recovered. They also observed other relays with the same pattern:

Another observation I made is the following, there are other relays with such a drop around April. 
They are also in South Korea[3][4][5][6], but also in Hong Kong[7][8], Singapore[9][10] and Japan[11][12][13].

In Taiwan there are Relays who grow from April on[14][15] and in South Korea as well[16][17].