Never listen to such advices.
Shift back to 5w30.
And use liquimoly 5w30 AAtec or 5w30 toptec 4200
Or you can use amsoil 5w30.
Both are outstanding imported oils with good oil change intervals. If it's a 4l sump you can go till 15k with toptec 4200 or molygen. If it's AAtec liquimoly then 8-10k.
And I'm a user of AAtec 5w30 in my Nissan sunny 2000 with A 1.8L engine.
And I'm as user of liquimoly molygen 5w30 in my liana 1.8L
I've used them in every condition, like scrotching heat, cold weather plus in hilly areas with extreme load. The performance was immaculate.
You should not go to 10w30 or 10w40 when you are already using 5w30.