After the restart, I can't attach redstone wire to redstone wire connector attached before the restart.

What version of IE and, in this case even more importantly, what other mods are you using?

Is this a visual only bug, as in is it still connected but just not visually so?

Have you tried with without Optifine?

1. That should probably be "without Optifine", not "with Optifine".
2. My guess would be Immersive Tech, they caused a problem like this before and while the bug is fixed on GitHub, the last version on CurseForge that I know of still has the bug.

ImmersiveEngineering-0.12-89

Baubles-1.12-1.5.2.jar
BetterFps-1.4.8.jar
BiomesOPlenty-1.12.2-7.0.1.2425-universal.jar
CTM-MC1.12.2-0.3.3.22.jar
Chameleon-1.12-4.1.3.jar
Chisel-MC1.12.2-0.2.1.35.jar
CoFHCore-1.12.2-4.6.2.25-universal.jar
CoFHWorld-1.12.2-1.3.0.6-universal.jar
CodeChickenLib-1.12.2-3.2.2.353-universal.jar
ComputerCraft1.80pr1.jar
ExpandedEquivalence-1.12.2-11b.jar
FTBLib-5.4.1.84.jar
FTBUtilities-5.3.0.81.jar
FastLeafDecay-v14.jar
Forgelin-1.8.2.jar
HammerCore-1.12.2-2.0.4.2.jar
Hwyla-1.8.26-B41_1.12.2.jar
immersivetech-1.12-1.3.10.jar
InventoryTweaks-1.64+dev.146.jar
IronBackpacks-1.12.2-3.0.8-12.jar
JustEnoughResources-1.12.2-0.8.9.48.jar
Mantle-1.12-1.3.3.39.jar
Mekanism-1.12.2-9.4.13.349.jar
MekanismGenerators-1.12.2-9.4.13.349.jar
MouseTweaks-2.9-mc1.12.2.jar
MrTJPCore-1.12.2-2.1.3.35-universal.jar
NotEnoughItems-1.12.2-2.4.2.240-universal.jar
OptiFine_1.12.2_HD_U_E3.jar
ProjectE-1.12.2-PE1.4.0.jar
RedstoneFlux-1.12-2.1.0.6-universal.jar
SimplyJetpacks2-1.12.2-2.2.10.63.jar
StorageDrawers-1.12.2-5.3.8.jar
TConstruct-1.12.2-2.12.0.115.jar
Thaumcraft-1.12.2-6.1.BETA26.jar
ThaumicJEI-1.12.2-1.5.5-23.jar
ThermalCultivation-1.12.2-0.3.2.11-universal.jar
ThermalDynamics-1.12.2-2.5.4.18-universal.jar
ThermalExpansion-1.12.2-5.5.3.41-universal.jar
ThermalFoundation-1.12.2-2.6.2.26-universal.jar
ThermalInnovation-1.12.2-0.3.2.11-universal.jar
TinkerToolLeveling-1.12.2-1.1.0.jar
TinkersComplement-1.12.2-0.3.0.jar
UniDict-1.12.2-2.9.2.jar
VeinMiner-1.12-0.38.2.647+b31535a.jar
WanionLib-1.12.2-2.2.jar
Wawla-1.12.2-2.5.269.jar
ancientwarfare-1.12.2-2.7.0.574.jar
bdlib-1.14.3.12-mc1.12.2.jar
buildcraft-all-7.99.21.jar
exnihilocreatio-1.12.2-0.3.7.jar
extrautils2-1.12-1.9.8.jar
forestry_1.12.2-5.8.2.382.jar
generators-0.9.20.12-mc1.12.2.jar
gravestone-1.10.2.jar
ironchest-1.12.2-7.0.59.842.jar
jei_1.12.2-4.14.4.264.jar
jeibees-0.9.0.5-mc1.12.2.jar
jeiintegration_1.12.2-1.5.1.36.jar
railcraft
railcraft-12.0.0-beta-4.jar
refinedstorage-1.6.12.jar
torchmaster_1.12.2-1.7.1.74.jar

When I uninstall Immersive Tech, I can attach redstone wire.
Thank you!