Since the latest update (March 2020). The REMOVEFILTERS function doesn't appear in the intellisense list.
e.g. Test = CALCULATE( [Sales], REMOVEFILTERS...........
Function is still valid if you type it in full and the intellisense then gives you the parameter help.
You may try earlier versions from Previous monthly updates to Power BI Desktop and also leave a comment on this blog.
Confirmed. I came here to report this myself and glad to see it was already done @MCornish. Thanks!