Why does Ctrl+Shift+V do something else now?
Some programs use Ctrl+Shift+V for plain-text paste, and Clip by Zaweba uses it for its popup. Here's why they clash and how to choose.

Ctrl+Shift+V is used by some programs, including Office, Chrome and VS Code, for their own paste as plain text. Clip by Zaweba uses the same keys by default to open its clipboard popup, and while Clip is running, the popup wins. If you'd rather keep the program's behaviour, change Clip's hotkey in Settings with one click.
It's a clash of habits rather than a fault, and there are two sensible ways to settle it.
What's going on
A keyboard shortcut can only do one thing at a time. When Clip is running, it listens for its popup hotkey across the whole system. Press Ctrl+Shift+V in Word or Chrome, and instead of the program pasting plain text, Clip's numbered list opens at your mouse pointer.
If you've only just installed Clip, this can look as though something's broken. It isn't. The program's shortcut is simply being answered by Clip first.
Option one: let Clip have it
Clip can paste plain text too. Open the popup with Ctrl+Shift+V, pick the item, and press Shift+Enter instead of Enter. Only the plain text goes on the clipboard, with no fonts, colours or links, so formatting from web pages and documents is stripped in exactly the way you wanted.
The bonus is that you can paste any item from your history as plain text, not just the last thing you copied. If the item you want is at the top, the extra step is one key.
Many people find they prefer this once they're used to it.
Option two: give Clip a different hotkey
If your fingers know Ctrl+Shift+V as plain-text paste and you'd rather not change, move Clip instead. Open Clip's main window from the tray menu, go to Settings, click the hotkey box and press the combination you'd like. Settings explains the clash so you know why you're doing it.
If you press a shortcut another program already owns, Clip tells you, and you can try something else. Avoid Ctrl+Alt+C, which Clip uses for Quick clip, and any hotkeys you've given your snippets.
Once it's changed, Ctrl+Shift+V goes back to doing what your programs expect.
Testing your choice
After changing it, try the new hotkey in each program you use most. Nothing else should happen when you press it except Clip's popup. If the popup won't open, check Clip is still running in the tray. As a fallback, left-clicking the tray icon always opens the popup.
Other shortcuts that might surprise you
Snippet hotkeys work from anywhere too. If you've given a snippet a hotkey such as Ctrl+Alt+1 and a program uses the same keys, the snippet wins while Clip is running. Clip checks clashes between its own triggers and hotkeys and won't save a duplicate, but it can't know about every program's shortcuts in advance, so pick snippet hotkeys you don't use elsewhere.
The quick answer
If Ctrl+Shift+V has started opening a list instead of pasting plain text, that's Clip by Zaweba. Use Shift+Enter in the popup for plain text, or change the hotkey in Settings. Either way, both features stay at hand.