Just to be sure, I have to:
- backup : https://doc.e.foundation/support-topics/backup-and-restore-ephone
- switch back to an “official” OS
2.1) download the ROM, found for oneplus 5T on https://service.oneplus.com/us/search/search-detail?id=2096229
2.2) follow /e/OS to Stock ROM on your smartphone using GNU/Linux - OnePlus Edition
- install the newest /e/
3.1) download the lastest zip on https://images.ecloud.global/dev/dumpling/
3.2) install it as i did a long time ago following https://doc.e.foundation/devices/dumpling/install
- profit
?