Play:1 and Play:3 not recognised in new S2 setup

I recently moved and decided to invest in 5 new One SL speakers. I also took my old system with me, consisting of two Play:1’s, a Playbar, a Play:3 and Play:5. The system was running on S1 because of the old Play:5. I am ditching the Play:5 because I want to move to the new S2 system. I tried to set up the new system by plugging the old Play:1 with an Ethernet cable in the modem. The S2 app told me to switch to the S1 app. I disconnected the Play:1 and used the One SL instead. This worked well, I managed to set up the One SL’s in the new S2 app, and those speakers work. But now I want to add the Play:1’s, the Playbar and the Play:3. But the problem is that the S2 app now suddenly cannot find them. Is there any way to make those speakers visible again?