For me the tp_rotate=1 did not work. What worked instead was the fix documented here reTerminalのディスプレイ向きを直す - Seeed K.K. エンジニアブログ and here reTerminal CM4 bullseye 64 bit issue Screen fix vertical · Issue #31 · Seeed-Studio/seeed-linux-dtoverlays · GitHub
cat ~pi/.config/monitors.xml
<monitors version="2">
<configuration>
<logicalmonitor>
<x>0</x>
<y>0</y>
<primary>yes</primary>
<monitor>
<monitorspec>
<connector>DSI-1</connector>
<vendor>unknown</vendor>
<product>unknown</product>
<serial>unknown</serial>
</monitorspec>
<mode>
<width>720</width>
<height>1280</height>
<rate>60.000</rate>
</mode>
</monitor>
<transform>
<rotation>right</rotation>
</transform>
</logicalmonitor>
</configuration>
</monitors>