Steps to Reproduce: See https://en.wikipedia.org/w/index.php?title=User:Jonesey95/sandbox&oldid=1010663816 which generates a Linter bogus image options error.
Linter reports a bogus image options error when a specified px value is present and the caption ends in "px".
Linter should not report an error.
This is yet another side effect of the failure of the Image parser to include an option to specify "caption=" to force a particular option to be the caption for an image.
This false positive can be worked around by adding an nbsp or any other text after the end of the caption.
This Linter false positive is new. It is probably related to the recent improvement deployed as a fix for T215999.