Don't expect a response from BlueTooth in your Button Click event block. It's too soon.
Instead, only do one BlueTooth input grab attempt in the Clock Timer, and use a global variable set in the Click event to tell it what it should be expecting.
You may need to switch to YAML format messages, because of message length limits.
Some people send temperature and humidity in separate messages with distinctive prefixes like "t:" (for temperature) and "h:" (for humidity).
(That's YAML format.)
The AI2 Charts component can recognize these and graph them. See Bluetooth Client Polling Rate - #12 by ABG
To receive YAML format messages, test if the incoming message contains ':' . If true, split it at ':' into a list variable, and find the prefix in item 1 and the value in item 2.