Hello chiu289,
Thanks for the additional information.
Based on the information you have provided, no Bluetooth device works with your iPhone's keyboard. We're glad to hear that your iPhone is fully updated. We have a couple of more questions to narrow down the cause of this issue. Is your Bluetooth device working to listen to music? Is this only happening with the keyboard dictionary? Have you checked your Privacy settings for any restrictions? Go to Settings > Privacy > Bluetooth. Then, go to Settings > Privacy > Microphone. Try unpairing the Bluetooth device and then pairing it again. We'd also recommend checking your Accessibility settings, go to Settings > Accessibility > Siri.
The articles below can help:
Restart your iPhone
If "Hey Siri" isn't working on your iPhone or iPad
Use parental controls on your child's iPhone, iPad, and iPod touch
If the steps above don't help, reach out for additional support here: Get Support