These are two unrelated faults and the fixes do not overlap. Nothing loading, with the channel list itself failing to appear, is a name-resolution or address-family problem: the app cannot reach the server at all. Video that starts, plays, and then drops to a blocky picture is a throughput problem: the connection is reachable but the carrier is capping what it delivers. Test by loading the channel list first. A list that populates proves the server is reachable over cellular, which removes half the internet's advice from consideration. A list that never appears means you are not connecting, and no bitrate or buffer setting is relevant yet.

1. 1List will not load: reachability
2. 2List loads, picture is soft: throughput

Mobile networks are built differently from home broadband. Many hand out IPv6 addresses only and translate to IPv4 at the network edge. That translation depends on hostnames being resolved by the carrier's resolver, so a stream address written as a bare IPv4 number rather than a hostname has nothing to translate and simply times out, even though your browser works perfectly. Carriers also place your traffic behind large-scale address sharing, which breaks anything expecting an inbound connection. Home Wi-Fi does none of this. So a service that works over Wi-Fi and fails on cellular is usually being carried differently, not blocked, and switching the resolver in the app or on the phone is the first thing to try.

1. 1Bare numeric addresses fail on IPv6-only mobile networks
2. 2A working browser does not prove a stream host is reachable

About 3 GB per hour at 1080p and roughly 7 GB per hour at 4K. HEVC encodes cut that to around half the bitrate of H.264 at similar quality, so a 4K HEVC channel can consume less than an older 1080p one. Those figures decide whether mobile viewing is realistic at all. A 15 GB monthly allowance is two hours of 4K. Plans that advertise a large high-speed bucket often deprioritize video specifically once you pass it, and the resulting ceiling frequently sits near 1.5 Mbps, well under the 5-8 Mbps a 1080p stream needs. That is why the picture degrades rather than stopping outright.

1. 1One hour of 4K is roughly 7 GB
2. 2Post-cap throttling often lands below what 1080p needs

Hotspot traffic is usually metered as a separate, smaller allowance and is often throttled harder than on-device data, so a stick fed by a phone can fail while the phone itself plays the same channel. The tunnel between the phone and the stick also reduces the usable packet size, and a stream that sends packets sized for home broadband will have them dropped or fragmented, producing stalls that look random. If you must run a streaming stick from a phone, expect to lower the stream quality rather than raise the buffer, and check the hotspot allowance separately from the main data allowance before blaming the service.

1. 1Hotspot allowance and phone allowance are usually different buckets
2. 2Reduce quality first, not buffer size

A short list, and it is the opposite of the usual advice. Raise the buffer rather than removing it, because a live stream arrives as roughly six-second segments and a cellular handover can stall delivery for longer than a small buffer covers. Pick a lower-bitrate or HEVC version of the channel where one exists. Set a public DNS resolver so name lookups do not depend on the carrier's. Turn off any battery saver that suspends background network activity. Then accept the limit: if the carrier has throttled you below 5 Mbps, nothing on the phone restores 1080p, and pretending otherwise just costs you an evening.

1. 1On cellular, a deeper buffer helps; on Wi-Fi, buffer-to-none usually does
2. 2Public DNS resolver, lower bitrate, battery saver off