The inlet air line is rather interesting - it must be said:

1. It is a bare thermocouple placed slightly upstream of the evap inlet filter - this explains the 'sensor chatter';
2. The hot water vessel, for his particular test (not the lab machine), is an open vessel - located in the test room. The upward drift during the major heating portion of the run, can be explained by hot water steam-off.

Please observe the correlation between the following signals:
#30 - air inlet temp
#27 - out exp
#28 - outlet evap
#29 - suction to comp

#27/#28/#29 track the air inlet temp, with moderation, but, the curve shape is visible - rise (with slight delay), peak, roll-off. The TXV seems to be doing pretty well, but, it simply cannot track closely, at evap fixed air speed.

The drifting air temp has to affect the Te,sat & associated evap temps. This can also be shown from an evap heat-transfer balance.