Nvstreammux (new) plugin is broken in DS 6.2 release

I use your code and ffmpeg rtsp server to test the fps. Add perf log as follows: Enable Perf measurement. Because there is no monitor on my device, I chose filesink.
The printing frequency is 1 second. After adding or deleting source, the nvstreammux batch algorithm requires some time to converge. But after stabilization, the frame rate is around 30.
Log:

Begin:
**PERF: 6.32 (5.09)     0.00 (0.00)     0.00 (0.00)
**PERF: 6.32 (6.29)     6.68 (6.63)     32.40 (29.24)
**PERF: 4.03 (5.40)     4.03 (5.25)     4.03 (5.61)
**PERF: 2.98 (4.73)     3.98 (4.82)     3.98 (4.83)
**PERF: 29.10 (10.02)   28.10 (10.75)   29.10 (12.70)
**PERF: 30.05 (13.59)   30.05 (14.67)   30.05 (16.95)
**PERF: 30.02 (16.08)   30.02 (17.26)   30.02 (19.52)
**PERF: 30.05 (17.91)   30.05 (19.10)   30.05 (21.24)
**PERF: 30.03 (19.32)   30.03 (20.48)   30.03 (22.48)
**PERF: 29.95 (20.43)   29.95 (21.55)   29.95 (23.41)
**PERF: 30.15 (21.33)   30.15 (22.40)   30.15 (24.13)
**PERF: 30.05 (22.07)   30.05 (23.09)   29.05 (24.61)
**PERF: 30.04 (22.78)   30.04 (23.75)   29.07 (25.10)
**PERF: 30.02 (23.31)   30.02 (24.24)   29.02 (25.42)
**PERF: 30.04 (23.77)   30.04 (24.65)   30.04 (25.77)

Delete 1 source:
**PERF: 30.06 (25.97)   30.06 (26.59)   30.05 (26.09)
**PERF: 29.04 (26.09)   30.04 (26.74)   0.00 (24.90)
**PERF: 29.03 (26.21)   30.03 (26.88)   0.00 (23.82)
**PERF: 30.04 (26.28)   30.04 (26.92)   0.00 (22.83)
**PERF: 29.11 (26.46)   30.05 (27.12)   0.00 (21.92)
**PERF: 29.04 (26.55)   30.04 (27.22)   0.00 (21.08)
**PERF: 29.05 (26.67)   30.02 (27.36)   0.00 (20.30)
**PERF: 29.05 (26.75)   30.05 (27.45)   0.00 (19.58)
**PERF: 25.64 (26.62)   26.75 (27.33)   0.00 (18.91)
**PERF: 25.40 (26.67)   32.24 (27.39)   0.00 (18.28)
**PERF: 33.14 (26.86)   29.20 (27.62)   0.00 (17.69)
**PERF: 27.22 (26.80)   28.80 (27.48)   0.00 (17.14)
**PERF: 33.52 (26.75)   22.68 (27.47)   0.00 (16.62)
**PERF: 27.79 (27.04)   37.73 (27.77)   0.00 (16.13)
**PERF: 28.71 (26.90)   27.22 (27.67)   0.00 (15.67)
**PERF: 27.61 (27.09)   32.27 (27.89)   0.00 (15.24)
**PERF: 27.39 (26.93)   26.91 (27.79)   0.00 (14.83)
**PERF: 27.63 (27.11)   32.57 (28.00)   0.00 (14.44)
**PERF: 25.95 (27.01)   30.01 (27.87)   0.00 (14.07)
**PERF: 32.40 (27.22)   28.43 (28.05)   0.00 (13.72)
**PERF: 29.04 (27.27)   30.04 (28.09)   0.00 (13.38)
**PERF: 30.01 (27.17)   26.24 (27.97)   0.00 (13.06)

add 1 source:
**PERF: 2.37 (25.51)    3.81 (26.32)    0.00 (11.43)
**PERF: 13.33 (25.29)   10.47 (26.01)   0.35 (11.40)
**PERF: 0.00 (24.79)    0.00 (25.50)    0.00 (11.18)
**PERF: 0.50 (24.34)    0.50 (25.03)    0.50 (10.98)
**PERF: 29.12 (24.45)   29.12 (25.12)   30.10 (11.36)
**PERF: 30.03 (24.55)   30.03 (25.21)   30.03 (11.71)
**PERF: 30.05 (24.65)   30.05 (25.30)   30.05 (12.05)
**PERF: 30.05 (24.74)   30.05 (25.38)   30.05 (12.38)
**PERF: 30.04 (24.83)   30.04 (25.46)   30.04 (12.69)
**PERF: 30.03 (24.92)   30.03 (25.54)   30.03 (12.99)
**PERF: 30.05 (25.00)   30.05 (25.62)   30.05 (13.29)
**PERF: 30.04 (25.09)   30.04 (25.69)   30.04 (13.57)
**PERF: 27.56 (25.13)   28.54 (25.74)   28.54 (13.82)
**PERF: 31.58 (25.23)   31.58 (25.83)   31.58 (14.11)
**PERF: 29.07 (25.29)   30.07 (25.90)   29.07 (14.35)
**PERF: 28.02 (25.33)   30.02 (25.96)   29.02 (14.58)