WFA3.1RC1 does NOT support in-place upgrade from WFA2.2 or WFA3.0
WFA3.1RC1 has laid the foundation for inplace upgrades in WFA. So inplace upgrdes will happen for an existing WFA3.1RC1 to a upward newer WFA version ( ex: WFA3.1RC2 or 3.1GA or anything above) which will be available in future releases.
Any WFA version lower than WFA3.1RC1 will have to go with the old Take Backup->un-install WFA->Install new WFA version -> Restore backup. So from 2.2 or 3.0 to 3.1RC1 , you need to do the same old way.
sinhaa
If this post resolved your issue, help others by selecting ACCEPT AS SOLUTION or adding a KUDO.