There are two potential problems with your code. First, you're not fetching the member collection and are instead interacting with the cache; if I remember correctly the cache usually only shows you online members and not offline ones. Second, the dreaded issue of rate limits.
The first issue is an easy fix. You just need to fetch the members instead of using the cache before all of your setInterval code:
setInterval(async () => {
const memberCount = (await guild.members.fetch()).filter(member => !member.user.bot).size;
const channel = guild.channels.cache.get('959556115383861298');
channel.setName(`╭・Members: ${memberCount.toLocaleString()}`);
console.log('Updating Member Count');
console.log(memberCount);
}, 5000);
That was probably causing the issue you were having. However, there's an additional problem here, one you will run into if you use this code. Rate limits. The normal rate limit for most actions in the Discord API is, if I remember correctly, 10,000 requests per 10 mins. However, the rate limit for changing the name of a channel is just 2 requests per 10 mins (last I checked; I don't know if they've increased this limit since last year). Your code is changing the name of a channel every 5 seconds. In just 10-15 seconds, you'll surpass the rate limit.
I have created channels that keep track of server stats for my bots in the past as well, and ran into this issue when I was doing so. Luckily, I brewed up a way to bypass the rate limit issue back when I was creating my own stats system. Though changing channel names has an incredibly low rate limit, fully creating channels has the normal rate limit of 10,000 requests per 10 mins. Therefore, instead of changing the channel name directly, you could instead: a) clone the channel; b) change the clone's name while creating it; c) set the clone's position in the channel list to the same position as the actual channel; d) delete the original channel. The cloned channel will keep all of the perms, settings, etc of the original. This all assumes, of course, that the original channel isn't a text channel with important messages or such inside, as those messages would all disappear with this method. I used voice channels for my system.
Here's how this bypass could look:
setInterval(async () => {
const memberCount = (await guild.members.fetch()).filter(member => !member.user.bot).size;
const channel = guild.channels.cache.get('959556115383861298');
const pos = channel.position;
const clone = await channel.clone({
name: `╭・Members: ${memberCount.toLocaleString()}`
});
await clone.setPosition(pos);
console.log('Updating Member Count');
console.log(memberCount);
await channel.delete();
}, 5000);
With this approach, rate limits are no longer an issue. Note that this can still be further improved, however. For example, inside the interval you could check if the member count has changed from the previous count, and only modify the channel name if and only if the count has changed. The entire approach potentially could be changed as well; perhaps you could use guildMemberAdd and guildMemberRemove events to track when the member count increases or decreases, and only modify the name when one of those happens (and only if the member being added/removed is not a bot). But whether to add either of those optional potential improvements is up to you.
Note: Please try this code out on a test channel before using it on the actual channel you are using, just to be safe.
