Clutch Pedal Sticking only in warm weather

My clutch pedal sticks in warm weather. It has happened 3 summers in a row now and it is not even that hot yet. I have replaced the clutch, the Master and Slave cylinder twice, WITH BMW parts and have had it bled 3 times. Still same problem. This time the pedal stuck as I was going down the freeway. Talk about scary. My mechanic told me I might need to replace the clutch pedal, but because the hydraulics come back in the evening when it cools off I am not convinced. Any suggestions?

Look down at the pedals.
Are they in alignment or is the clutch pedal splayed out to Driver's left?
If yes, the bushing at the pedal box needs to be replaced.
If you have ignored the problem for too long, there's a strong probability that the mounting brackets for the pedals are warped or torn.

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