For me, ABRP does not recognize the language module.
At each APP start appears the message that the language module is not installed. When I click on the button I get to the store where I see that it is already installed.
Google TTS is definitely installed. The language is also available offline. With HERE WeGo it also works without problems.
ABRP Version 4.6.1(2434)
Google Pixel 4 with LineageOS, MicroG and AA4MG installed.
All other Android Auto Apps work fine.