BossBar still not showing up with fabric 1.14.4 client on spigot 1.8.8

[RaphiMC]

Describe the bug, provide any errors Setup: 1.14.4 Fabric with ViaFabric installed. If you summon a wither the bossbar will not appear on the ViaFabric client.

How can we reproduce it? Steps to reproduce the behavior:

1. Select version 1.8 in ViaFabric and join a spigot 1.8.8 server
2. Summon a wither
3. No BossBar will appear

Expected behaviour A BossBar showing the health of the wither

Screenshots http://prntscr.com/t6pryu

ViaVersion Dump:

• Can't do that in ViaFabric. I use the latest ViaVersion and ViaFabric version (downloaded 26.06.2020)

Additional server info No plugins were present on the test-server.

[RaphiMC]

I created a new issue because the old one got closed and the bug remained

[RaphiMC]

Yes (the latest one)