Comment by Kortaggio

A few more for your list:

https://altvr.com/

https://borrel.app/

https://calla.chat

https://cozyroom.xyz

https://cubechat.io/

https://gather.town/

https://happyhour.ianwdavis.com/

https://here.fm

https://hopin.to

https://icebreaker.video/

https://makespace.fun

http://mcparks.us

https://metaversehq.com/v/room

https://mixaba.com/

https://party.vipshek.com

https://rally.video/

https://rambly.app/

https://recroom.com/

https://remo.co/

https://sine.space/vr/

https://slashtalk.com

https://spatial.chat/

https://squadapp.io/

https://tivolicloud.com/

https://town.siempre.io

http://vircadia.com/

https://virus.cafe

https://wavexr.com/

https://welcome.topia.io/

https://www.airmeet.com/

https://www.banger.digital

https://www.brella.io

https://www.highfidelity.com/

https://www.huddlehq.io/

https://www.ivent-uk.com/

https://www.joinglimpse.com

https://www.kitely.com

https://www.muze.nyc/

https://www.sansar.com/

https://www.somniumspace.com/

https://yorb.itp.io

https://zonko.chat/