Portals disappear randomly

[Caelanj]

Inside the nether portal just completely disappears, it seems like its when you get too far away, almost like the portal despawns. Look just looks like an unlit portal.

This is on forge server running these mods, we had a creative server for testing and had no problems like this, then as soon as we went to survival we started getting this problem. List of mods: (yes i know its a lot)

aether-1.12.2-v1.5.3.1.jar animalnet-v1.12.2+b3.jar AoA3-3.3.1.jar betterportals-0.3.7.7.jar buildcraft-all-7.99.24.8.jar CodeChickenLib-1.12.2-3.2.3.358-universal.jar Commons0815-1.12.2-1.4.0.jar Computronics-1.12.2-1.6.6.jar EnderStorage-1.12.2-2.4.6.137-universal.jar energyconverters_1.12.2-1.3.7.30.jar Forgelin-1.8.3.jar ForgeMixinFix-1.0.0.jar Galacticraft-Mod-1.12.2.jar jei_1.12.2-4.16.1.301.jar MicdoodleCore-1.12.2.jar MobGrindingUtils-0.3.13.jar mtqfix-1.12.2-1.1.0.jar mystcraft-1.12.2-0.13.7.06.jar NoMoreRecipeConflict-0.13(1.12.2).jar OpenComputers-MC1.12.2-1.7.5.192.jar OpenGlasses-MC1.12.2-2.2-50.jar twilightforest-1.12.2-3.11.1021-universal.jar

[festro]

Have the same issue, would be great to get a command to refresh portals (edit )after disabling MobGrindingUtils the end portal reappeared.