feedback and question on PPP positioning

[flex0902]

Dear developer,
This is my feedback and questions:
I use RTKPOST ver "b34c" for PPP kinematic positioning and it usually can produce nice results (not best, but acceptable).
However, I find the other newer version, for instance "b34g, b34i", may not give same quality results as b34c.
I used the same parameters in the OPTIONS of RTKPOST. Here are the PPP results of an IGS tracking station from b34c and b34i, respectively.
From b34c

From b34i

In addition, it seems that the RTKLIB cannot pair the antenna type between the RINEX and ATX file. when I trace the residuals to level 4, it always show " 2 no receiver antenna pcv: TRM59900.00 SCIS", even the antenna type is included in the IGS14 or IGS20.atx file. Another evidence is that there is no change in PPP positioning results when changing different antenna type with delta E/N/U = 0 meter. The output values of the dant[0] and dant[1] are always the same. Does this mean that there is no correction from PCO to APR? I am not familiar with the coding works of RTKLIB, therefore, I can't confirm if this is actually a bug in readpcv, readantex, searchpcv or setpcv.