On Thursday, 25 March 2021 at 21:58:22 UTC, T i m wrote:

Yesterday I investigated when we took the dog for a walk last thing
and it appears at least one manhole cover has been lifted ... or has
worked loose(?) and is now rocking about 5mm when you stand on it?

Could you pop out at night, lift a corner and wedge a window glazing packer or similar underneath?