Teacher retirement income from KS/OK/TX, now residing in Arkansas

My husband is a retired teacher with teaching retirement income from Kansas, Oklahoma and Texas.  We lived in Texas until July 2019 and now reside in Arkansas.  Texas does not have state income tax but Arkansas does. Are we required to file an Arkansas state income tax return for the retirement income he's received since we moved to Arkansas (July 2019) or is the retirement income from states other than Arkansas exempt?  TIA