Orbi loses connection on some devices but not others

Hello. We have an Orbi mesh system in our home which recently started dropping connection with only some devices but not others. For example, we will lose connection first on our iPhones, then on one laptop (surface pro), later another laptop (acer), but our streaming tv remains connected and unaffected until we turn the tv off. We are able to reestablish connection by unplugging the system and spectrum modem, but we lose connection again within 12-24 hours. We have installed the latest firmware which has not improved the issue. Any advice? Thank you.