you got the same repaint related problem like me,
i cover it with 1 layer of nippon matex ,  but another layer is needed to completely cover it,
the rest of the wall, not yet done, an paint expert uncle suggest us put sealer 5400 before color paint, we makan the word he say ' it will last longer' because we lazy to repaint it after a decade or so...
some sifus here suggest that good wall without chalking feel can just paint with matex or maxilite , if you got the budget then (expensive ) sealer will also do
i learnt a lot bout paint here! so graceful

can can
Thanks for sharing bro, you mean paint 2layers or more of nippon matex able to cover up wall? for last longer suggest better paint sealer 1st layer the 2nd layer paint nippon matex?no need sand off the existing wall colour?

because my wall is painted this not so fancy color as in the picture, i was having a headache solving it, from forum, i learnt that it can be rather easy( may depends on your wall condition), these wall i think it painted not more than 5 or 6 years ( it's a subsale house) and the wall is not chalky and powdery, when we rolling the matex on the surface, no paint fragment fall off, this previous paint stick so well to the wall...
actually i want less work, if expensive abit i dont mind. which way better
1. use nippon matex white paint 2layers
i got my response from sifus about  maxilite but i ended up purchased nippon matex, i didint come accross maxilite , but imo i think the matex texture is more thick i can say, it dried pretty fast ( we opened the glass sliding door but turn on no fan in the late evening

only 1 layer
1 or 2 layers really depend on its coverage, mine need 2 layers for retouch, we not yet retouch second layer even now
as you can see from the picture, my wall surface (i figured out it is a special paint technique using machine paint gun to spray and form a thick pigmentation wall) and the matex layer is not even, so you still can see the red still can be seen in some spot 

from what i red in this forum, if the wall still nice to touch and no peeling or yellow staining caused by moisture, we just can paint a new layer direct on it without sanding or peel off the previous paint, sanding is so difficult and waste tons of time and its so dusty

for  me, i want white series color paint on my dark tone wall , i have to repaint it with white (sealer (today going to buy it and try it on to see how many sealer i need to apply, maybe  in a day or two for another purple wall) or matex/ maxilite)
if you desire a darker paint on your current wall, can just paint over like jotun monsoon cloud color (please correct me if im wrong)

2. paint sealer 1st layer and 2nd layer paint nippon matex white
im positive on the sealer as the 1st layer for a better foundation, but matex as the finishing  im not so sure about it lar, let's wait for other to share theirs
(because hor , some say matex or maxilite will slowly luntur of come off after ages and even when you cleaning a stain on it  with a damp cloth/ kain buruk)

3. use primer for 1 layer (i saw some bro suggest sand it,then 1st layer nippon matex 2nd layer primer can last longer, not sure is work? but i dont want sand it)
im dont know what is primer actually, i just so into sealer and paint brand only,, wish to know more what is primer and its purpose too
yesterday i came across a youtuber sharing bout paints and preparation before painting, i havent finish it coz my internet and wifi so broke  
try to watch it if you can understand mandarin, its consists so much info and hope it clear you out

Maxilite is for first coating.. only..
In chinese, we called it 'chui chat'

You need actual paint like nippon / dulux ... for permanent layer