Bug Description

After creating plastic in Age 3 (using the diesel Boiler for steam), I advanced to Age 4.

Then, I decided to switch to Solar Tower steam. I put it in the Chemical Mixer (with naphtha), no luck ("no valid recipe").
I rebuilt the Boiler, put the steam in the Chemical Mixer, same issue.

Did this behavior use to work in the previous version?

Steps to Reproduce (for bugs)

1. Complete plastic creation in Age 3, using steam from Boiler
2. In age 4, create Solar Tower and try to use steam for molten propane creation in chemical mixer (it fails)
3. Then, try to use again steam from Boiler. It fails again.

Logs

• Client/Server Log:
• Crash Log:

Client Information

• Modpack Version: 3.1.15 (updated using Twitch from 3.1.12 Hotfix 1)
• Java Version: 1.8.261
• Launcher Used: Twitch
• Memory Allocated: 8192
• Server/LAN/Single Player: Single Player
• Optifine Installed: No
• Shaders Enabled: No

World Information

• Modpack Version world created in: 3.1.12 Hotfix 1
• Additional Content Installed: No

UPDATE:
[Next day] After a computer reboot and a complete tear-down and rebuild of Chemical Mixer, it works ...
Both with Boiler and Solar Tower steam.