Yes as others have said 100% common. Grief makes people go a bit mad.
If it's the death of a parent, this is almost standard because (and I didn't realise this at the time and with hindsight feel a bit naive as it's so obvious) all the children (if there are more than one) will have different relationships with the deceased.
It is likely that there will be at least one who perceives another one to be 'a favourite' child which the death will bring out in terms of triggering years of unspoken resentment.
A parent, especially a mother, can be the lynchpin holding the whole family together. When they die, it can mean that the centre of gravity of the family has gone and everyone is scrambling to re-adjust in a new dynamic.
If you loved the deceased it is so SO SO terrible to be dealing with grief and having to organise stuff.
The only thing I would say is to remember that every is having a hard time, remember this and cut each other some slack. Say this repeatedly to everyone involved. Tell everyone that we are all grieving in our own way and we all need to make allowances for each other.
Insofar as possible, everyone who matters/close relatives should be able to have input and their way because there is one funeral, feeling heard and seen is important in times of grief and what is important to one about honouring the deceased is not to another.
So what I mean by that is if A really wants Hymn 1 and B really wants Hymn 2, don't fight about it and have both of them. Compromise if it doesn't really matter to you and it won't bug you for ever.
I'm sorry for you loss. Death is just pain for those left behind.