i reported u same issue about text editor and u tnx for fixing it
repeatedly For Document viewer also too it shouldn't opens
more than one window opens from same file please don't allow
Document viewer reopens a same file that from already has been opened as minimized bulb in new document viewer windows by clicking
on that file in your FileBrowser or from other full featured file browsers

it is shameful all things must be reported by users otherwise u developers never would know about them this shows u developers yourselves never use floating apps as your Apps you yourselves has developed it

upgrade for popup dialog When clicking on a txt or doc... files in FileBrowser
1-when clicks on a .docx file in FileBrowser when document viewer opens it please add an Edit pen button on Document viewer toolbar to able editing it in Microsoft Word or other full featured apps immediately , I know it is already possible by longpress on the docx file and choose open with.. option. i just say if u add edit pen button on Document viewer toolbar can open Microsoft Word(if installed) immediately directly without viewing Android "open with.." dialog imagine if u wrongly click on suggested apps in Android "open with.."dialog then always this docx file opens with that wrongly selected app!

2-when clicks on a .txt file in FileBrowser when a popup dialog opens and says : "Do u want to Edit or View he file?" please add an radio option in this dialog asking: "Remember the choice & Dont ask again"
then :
if user choose and clicks on popup dialog view buton, user will edit it by clicking on Edit Pen button on Document viewer Edit toolbar or Edit option in its context menu

but

if user choose and clicks on popup dialog Edit button , after running TextEditor user will back to just view it in Document viewer by adding an switch toggle button on texteditor title bar or in its context menu and abandon the "Remember the choice & Dont ask again" presets in popup dialog and the dialog restarts for each time clicking on a txt file again

There is a similar idea already, but my point is to also make the customization of the trigger area width possible.
I have a S9+ with curved screen edges and which makes it harder to open the menu. Probably as well because of an option that's ment to block unintended touch inputs, I guess especially at the edges which is useful in general.
Also phone cases that go far around the egdes make it more difficult to open the menu quickly and conveniently. Same if the margin between skin and phone frame is very slim, your finger always hits the edge of the phone body before the edge of the screen and may miss the second one then.