There are 6 quests from these, diamond singularity being the first, and the neutronium compressor doesn't accept the blocks properly. It takes them and counts up, but it isn't actually counting up. The titanium one also behaves in the same way. They aren't used for anything else, so it doesn't stop progression, except the fact that you can't complete those 6 quests for them. I'l probably see if it'll work with spawned in stuff in single player and report back if it make s any difference. Edit: Ok I tested in singleplayer, spawned in a creative strongbox, neutronium compressor and pipe. It works with both putting in the diamond blocks manually, and piping them in from the strongbox.
Thank you for contacting us regarding this issue, I have gone ahead and made an adjustment to the crafting recipe. I have tested with the diamond singularity and was able craft it with no problems. At this time I will consider this as resolved and close this thread. If for any reason you still have issues with this please respond back and we will reopen and investigate the case. Thank and have a great day.