When using backup/restore to copy data to another database, "-since" works and "-start" doesn't work


Source DB is on Raspberry PI 3B, Raspbian 9.9, influxdb version 1.7.6-1 from “deb InfluxDB - Package Repository stretch stable” and target DB is on amd64, running FreeBSD 11.2-RELEASE-p9, influxdb version 1.6.2 built from ports.

Data is copied using backup and restore, below is relevant part of the shell script that copies data.

start_time="$(influx -host target -database 'ruuvi' -execute 'select time,mac,temperature from ruuvi_measurements ORDER BY time DESC LIMIT 1000' -format 'csv' -precision 'rfc3339'|awk -F',' 'END{print $2}'|sed -e 's/\(T[0-2][0-9]:[0-6][0-9]:\)\(.*\)/\100.000Z/')"
influxd backup -portable -since "${start_time}" ~/influxdb_backup/${start_time} && \
influxd restore -portable -host target:8088 -db "ruuvi" -newdb "ruuvi1" ~/influxdb_backup/${start_time} && \
influx -host target -execute 'SELECT * INTO "ruuvi"."autogen".:MEASUREMENT FROM "ruuvi1"."autogen"./.*/ GROUP BY *' && \
influx -host target -execute 'drop database ruuvi1' && \
rm -rf influxdb_backup/${start_time}

If I change “-since” to “-start” data does not end in “ruuvi” database on host target, although I get the same output from “SELECT * INTO”, for example:

name: result
time written
---- -------
0    297284