(trick) A workaround for Tiled Window Manager
A tiled window manager (TWM) (like Actual Window Manager) is a program to quickly arrange resized/small window into place for purposes (multitasking, make windows looked neat, etc.,). It works just like window's snap function but much better.
Normally Vivaldi can snap to window function well but can't apply other TWM well. I found a way that just click the Closed Tabs button (the bin) and then try again. Here are some picture to visualize what I mean:
Before clicking the button:
Click the Closed Tabs button:
And the result:
Weird but it works. I underwent the manual sesizing for months before finding this but Vivaldi was good enough to keep me using.
Just wanna share a trick for somebody who get the same issue as me. Changing to Native window in option works too (but it's not so good looking).
I wonder if enabling the native window mode would improve its compatibility.
Replied before I read the whole post, nevermind.