Had to set TTL and HL (IPv6) to 88. 65 doesn’t work anymore.
Also, had to change the APN from ‘internet’ to ‘VZWINTERNET’ because when on the ‘internet’ APN, downstream would be fine, but after about 60s, the upstream becomes throttled to “hotspot” speeds (e.g. 2-5 Mbps). Changing the APN to ‘VZWINTERNET’ solved the upstream/upload throttle.
EDIT: This was on a Puli AX (GL-XE3000) which is basically the same as a Spitz AX.