Unfortunately, unlike principal authorities, the government have failed to make legislation to subject town and parish to the scrutiny of the Local Government ombudsman. My suggestion would be to raise the matter with the principal authority monitoring officer as a potential breach of your parish council code of conduct. However you would have to read it to see if it includes the articles of the model code of conduct,which it isn't obliged to do. Those who include it undertake to :
I Act with integrity and honesty
Act Lawfully
Treat all persons fairly and with respect; and
Lead by example and act in a way that secures public confidence in the role of councillor.
In undertaking the role:
Impartially exercise responsibilities in the interests of the local community
Don't improperly seek to confer an advantage, or disadvantage, on any person
Avoid conflicts of interest
Exercise reasonable care and diligence; and
Ensure that public resources are used prudently in accordance with local authority’s requirements and in the public interest.
By excluding you from a meeting it could be argued there has been a breach of the model code of conduct in that the chair (other councillor or clerk at the meeting) has acted unlawfully and sought to confer a disadvantage on you by not allowing you to exercise your right to attend and film too maybe.
If the monitoring officer says the complaint doesn't apply or argues they don't want to get involved, you could report that MO to the local government ombudsman, who may if they agree with you acknowledge the PC acted unlawfully and advise the MO to reconsider their lack of action.