Missing rows after join()

This morning I noticed some missing points in my graph.
After some investigation I concluded that the points where missing after the join() and not before.

Following an example to reproduce my problem:
example:

import "csv"

csvData1 = "
#group,false,false,false,false
#datatype,string,long,dateTime:RFC3339,double
#default,_result,,,
,result,table,_time,_value
,,0,2021-09-29T07:00:00.05Z,6004.5
,,0,2021-09-29T08:00:00.088Z,4036.375
,,0,2021-09-29T09:00:00.097Z,5003.625
,,0,2021-09-29T10:00:00.11Z,6602.375
,,0,2021-09-29T11:00:00.075Z,6515
,,0,2021-09-29T12:00:00.126Z,6506
,,0,2021-09-29T13:00:00.075Z,8890.75
,,0,2021-09-29T14:00:00.048Z,4020.25
,,0,2021-09-29T15:00:00.089Z,5045.375
,,0,2021-09-29T16:00:00.126Z,6208.125
,,0,2021-09-29T17:00:00.049Z,17822.75
,,0,2021-09-29T18:00:00.077Z,52578.125
,,0,2021-09-29T19:00:00.09Z,45923.75
,,0,2021-09-29T20:00:00.056Z,44170.5
,,0,2021-09-29T21:00:00.091Z,6878.75
,,0,2021-09-29T22:00:00.139Z,86.875
,,0,2021-09-29T23:00:00.048Z,51.375
,,0,2021-09-30T00:00:00.096Z,53.375
,,0,2021-09-30T01:00:00.085Z,53.125
,,0,2021-09-30T02:00:00.029Z,53.375
,,0,2021-09-30T03:00:00.13Z,51.625
,,0,2021-09-30T04:00:00.091Z,50.875
,,0,2021-09-30T05:00:00.074Z,505.625
,,0,2021-09-30T06:00:00.052Z,1889.25
"

csvData2 = "
#group,false,false,false,false
#datatype,string,long,dateTime:RFC3339,double
#default,_result,,,
,result,table,_time,_value
,,0,2021-09-29T07:00:00.05Z,2275
,,0,2021-09-29T08:00:00.088Z,1341.3125
,,0,2021-09-29T09:00:00.097Z,1539
,,0,2021-09-29T10:00:00.11Z,1888.1875
,,0,2021-09-29T11:00:00.075Z,1890.8125
,,0,2021-09-29T12:00:00.126Z,1877.75
,,0,2021-09-29T13:00:00.075Z,3736.8125
,,0,2021-09-29T14:00:00.048Z,1361.9375
,,0,2021-09-29T15:00:00.089Z,1497.25
,,0,2021-09-29T16:00:00.126Z,1723.75
,,0,2021-09-29T17:00:00.049Z,7509.1875
,,0,2021-09-29T18:00:00.076Z,23224.5
,,0,2021-09-29T19:00:00.09Z,21039.6875
,,0,2021-09-29T20:00:00.055Z,21155.6875
,,0,2021-09-29T21:00:00.091Z,3163.0625
,,0,2021-09-29T22:00:00.139Z,10.375
,,0,2021-09-29T23:00:00.048Z,1.125
,,0,2021-09-30T00:00:00.096Z,0.875
,,0,2021-09-30T01:00:00.085Z,1.0625
,,0,2021-09-30T02:00:00.029Z,0.9375
,,0,2021-09-30T03:00:00.13Z,0.6875
,,0,2021-09-30T04:00:00.091Z,0.6875
,,0,2021-09-30T05:00:00.073Z,123.1875
,,0,2021-09-30T06:00:00.052Z,598
"

t1 = csv.from(csv: csvData1)
t2 = csv.from(csv: csvData2)

join(tables: {t1: t1, t2: t2},on: ["_time"])

result:

#group,false,false,false,false,false
#datatype,string,long,dateTime:RFC3339,double,double
#default,_result,,,,
,result,table,_time,_value_t1,_value_t2
,,0,2021-09-29T07:00:00.05Z,6004.5,2275
,,0,2021-09-29T08:00:00.088Z,4036.375,1341.3125
,,0,2021-09-29T09:00:00.097Z,5003.625,1539
,,0,2021-09-29T10:00:00.11Z,6602.375,1888.1875
,,0,2021-09-29T11:00:00.075Z,6515,1890.8125
,,0,2021-09-29T12:00:00.126Z,6506,1877.75
,,0,2021-09-29T13:00:00.075Z,8890.75,3736.8125
,,0,2021-09-29T14:00:00.048Z,4020.25,1361.9375
,,0,2021-09-29T15:00:00.089Z,5045.375,1497.25
,,0,2021-09-29T16:00:00.126Z,6208.125,1723.75
,,0,2021-09-29T17:00:00.049Z,17822.75,7509.1875
,,0,2021-09-29T19:00:00.09Z,45923.75,21039.6875
,,0,2021-09-29T21:00:00.091Z,6878.75,3163.0625
,,0,2021-09-29T22:00:00.139Z,86.875,10.375
,,0,2021-09-29T23:00:00.048Z,51.375,1.125
,,0,2021-09-30T00:00:00.096Z,53.375,0.875
,,0,2021-09-30T01:00:00.085Z,53.125,1.0625
,,0,2021-09-30T02:00:00.029Z,53.375,0.9375
,,0,2021-09-30T03:00:00.13Z,51.625,0.6875
,,0,2021-09-30T04:00:00.091Z,50.875,0.6875
,,0,2021-09-30T06:00:00.052Z,1889.25,598


There are 2 rows missing …
Between timestamps 2021-09-29T17:00:00 and 2021-09-29T19:00:00 and
between timestamps 2021-09-29T19:00:00 and 2021-09-29T21:00:00.

I am running a InfluxDB v1.8.6 on Debian 10.

Output of

import "runtime"
runtime.version()

is error calling function “version”: build info is not present :wink:

Can someone please help me with that. thx