Dependant Visa Uk - Can it be revoked?

[Nonna]

Good Afternoon,
I hope you are all well.

I have an unusual question I guess, and I am really worried now.

My child and I have been granted a UK dependant/spouse visa and have relocated from Canada in March of 2016 to join my husband and my son's stepfather. I have not left UK since then, but my 15 year old son has gone for a visit to Canada in December of 2016 and has surprisingly decided to stay there until the summer. He is planning on coming back to The UK in July of this year. My question is, has my son now lost the right to live in the UK since he has been away since December 2016?

Should I be anticipating any problems with entry to the UK, even just for a visit?
Some important points are:
- I have sole custody if my son
-I have a Canadian Family Law permission to move to the UK with my son
-my son has a valid Canadian passport and a UK Biometric Residence card ( expiring End of 2018).

Please help!
Many thanks in advance.

[vinny]

He should be okay, if he returns prior to his leave's expiry date, provided his circumstances and purpose are unchanged. Who is going to look after him there?

[Nonna]

Many thanks Vinny! My son is staying with family in Canada now , grandmother and uncle. I still have sole custody of him, so nothing from that point has been changed. In the UK , he will continue living with me and the Stepfather

[vinny]

Provided his purpose and circumstances haven't changed when he returns, he should be okay.