This connectors and relay is connected with LV wire, but it is not visible. MV and HV wires are not visible too.
Without Rubidium wires are visible.
Rubidium version: 0.6.4
MC version: 1.19.4
Forge version: 45.0.63
Immersive Engineering version: 1.19.4-9.4.0-166

Having same issue.
Same Mod versions,
Forge Version 45.0.64

Without Rubidium:

With Rubidium:

this issue is still occurring for me as well on the most up-to-date versions of everything. quite annoying, as my friends game is unplayable on our modpack without rubidium.

1.19.4 is abandoned