Its looks working in Windows for us, Can you help in re-creating the scene/bug. Can you explain how you are executing copy-paste.
Are you able to copy/paste in notepad/wordpad etc. or just Dero wallet.
I copied the seed string by selecting the text with my cursor then hitting ctrl-c to copy. Then I opened an administrator command prompt and pasted the string into it using both ctrl-v and right clicking the mouse and selecting paste - both worked.
So pasting into a command prompt works fine, as it always has in Windows 10.
Trying to recover from seed again, when I hit ctrl-v to paste it shows a non-printable single character; looking closer, it appears to be a ? in a box, so I guess that translates as "unprintable character".
I cannot right-click while sitting at the "Enter seed (25 words):" prompt. Trying again, I also cannot paste using either method to the password prompt.
Right clicking on the title bar for the command window that the wallet is running in and selecting "Properties" I also checked the checkboxes under "Options" and all were enabled EXCEPT for "Quick edit mode," but enabling Quick edit mode didn't change anything. Still can't paste.
And yes, copy-and-paste works fine elsewhere.