You need to adjust the phase to get normal shaped peaks (there are 3).

Phase adjusting should give you the clear NMR spectra. The buttom is "phase correction" in mestre software (it shows the pattern that you are reporting).

Dear Alexander,

As other colleagues have already commented, it is a phase adjustment problem. You could see the following link (from RG) about this:

https://www.researchgate.net/post/I_got_a_13C_NMR_peak_which_appeared_in_reverse_phase_of_the_base_line_What_does_this_mean .

Best,

Fran

Dear Alexander,

You can also see the following links:

https://www.youtube.com/watch?v=hU0Pu3Fmsz4

https://www.youtube.com/watch?v=guMWaZArkjM

Best,

Fran

Dear Alexander,

This other link may also be useful for you:

https://nmr.chem.ucsb.edu/education/part1.html

Best,

Fran

I never heard that NMR spectrometers produce "chromatograms" before... that's an exciting new experience.