The College of Arms keeps us informed of the correct flag-flying protocols.
“Any Ukrainian flags that are currently being flown should be taken down from 08.00 Saturday 11 November (Armistice Day) to 20.00 Sunday 12 November(Remembrance Day). (3November)
Further to the notice distributed on 3 November, further advice has been received that those currently flying the Ukraine flag need not take it down for Armistice Day and Remembrance Day, 11 and 12 November. (6 November)
Enquiries regarding the correct protocols for the flying of Union and other flags should be addressed to the Officer in Waiting at the College of Arms in the first instance.” (College of Arms, 6 November)
You may wish to consult the College on the advisability of flying flags of other nations. I occasionally sport the Nepalese flag, not wishing to attract controversy.