Can I continue on Tier 1 dependent visa after husband becomes British citizen

I am currently on Tier 1 dependent visa valid till May 2019. While returning from a trip, the immigration officials at Heathrow Airport told me that my Tier 1 dependent visa is no longer valid as my husband has now become a UK citizen. They asked to apply for family/spouse visa.
I was granted Tier 1 dependent visa on my 1st entry to UK and a 3 year extension given later when my husband was holding a ILR. They let me into the UK this time with a warning but told me that I may be refused entry next time if I don't apply for spouse visa.

I was reading the UKBA rules which seem to suggest that my current visa should be valid. Could you please let me know if my understanding is correct ? Also, how do I avoid problem at the airport next time I travel?

Please see below for the relevant UKBA rules and details on various timelines.


UKBA rules

https://www.gov.uk/government/uploads/s ... n_2017.pdf

The document above on Page 4 states that
You can apply as a PBS Dependant if you meet the criteria set out in this guidance and the
Immigration Rules and you are:
the spouse or partner of a person with indefinite leave to remain or British Citizenship who last
held leave in Tier 1, 2, or 5 of the Points Based System and you do not yet qualify for indefinite
leave to remain; or

(I will be eligible for ILR only in May 2018 as I entered the UK in June 2013)


Timeline
I entered the UK in June 2013 on Tier 1 dependent visa post marriage.
My husband switched to ILR in 2014
I applied for extension of Tier 1 dependent visa in May 2016 (while my husband was on ILR). I was granted a visa valid till May 2019.
My husband became a British citizen in December 2016.

Thank you

I think that you understanding was correct and these Immigration Officers were mistaken.

Thank you. I am not sure what to do to ensure i dont get stuck at the airport next time we travel.

I have heard similar stories like you but only when the main applicant (your husband on this case) was on tier-1 but settled via different (Long residency) route. In such situation they advise the dependent to move ASAP to family/spouse visa.

May be you can only explain them that your Husband got the settlement based on Tier-1 (if it is), Hence you can continue on the current category.

i did try to explain the immigration official about it at that time and she told me that till he was on is Tier 1 or ILR it was fine, but now that he is citizen, i should have a spouse visa.

I am very confused about further plan. Any input will be really appreciated

Vinny's advice and links are correct.