For a very long time I have had no issues with Node-RED and the gSheet plugin and today I decided to add some more cells to the look-up and place it into HomeAssistant (that's where everything else goes).
Out of the blue cell look-ups that had previously been working without any issue decided to give a random number (that wasn't correct) and now it simply says "Loading..." when I attach a debug node to it.
Keep in mind this part of the spreadsheet has been untouched and the nodered flow has also been untouched. I have checked and verified several times that the felids are correct and correlate together.
That suggests it is an issue with connectivity or google rather than node-red. Open the browser developer tools and see if there are any errors shown there.