Find & Replace [contains] Bug?

If I try to Find & Replace a word using the ‘contains’ option, words at the start of a note are not replaced. For example setting Find Options to ‘contains + Ignore Case’ then specifying Find=“Blue” and Replace=“Red” and clicking ‘Replace all’ on a note starting with:

Blue coats are always blue in colour

the results are:

Blue coats are always Red in colour

instead of:

Red coats are always Red in colour

To achieve the latter it is necessary to run the replace twice - first with the ‘contains’ option, then again with the ‘Starts with’ option - after which all occurences of ‘Blue’ are correctly changed to ‘Red’.

Is this behaviour as expected - or is it a bug?