Issue with Bitcoin transaction delays

Hey, sorry to bother everyone with this. I sent some bitcoin to a crypto wallet, and it took a whopping 3 days for it to show up in my wallet. Any idea what might've caused this hold-up?

Low transaction fee is the reason. To check the fee for high priority with fast confirmation, you can use https://mempool.space/ to know the fee rate to be used. Another one is https://jochen-hoenicke.de/queue/#BTC,24h,weight

Just as it's been said it's likely to be the transaction fee, if it's low compared to other unconfirmed transaction it will  have to wait in mempool to get picked. It's not a glitch  nor bug besides, I don't know if you were sending from exchange as it's likely to occur when you send through exchange wallet sometimes if the transaction fee setted by the exchange is low. if it's not exchange wallet, then make sure you check the prior.set it before sending your bitcoin.

If it took 3 days then it wasn't a glitch if the fee you paid is around 3 to 6 sats per byte because 3 days ago the recommended fee was around 20+ sats/vb. Another reason I think you might be using a Mycelium wallet which is known as buggy and always has a slow connection if you are using this then maybe after you made a transaction 3 days ago the transaction just stuck in Mycelium itself without broadcasting the transaction online and then recently you open Mycelium and the transaction just broadcasted because their server maybe online. Why not tell us first what wallet you are using? Why do you end up with any of these reasons?

You need to share what is the crypto wallet you sent your bitcoin to. It is important information because there are two possible destinations for your bitcoin. #1: The address belongs to your account on an centralized exchange or an online platform. That is custodial wallet, and you don't own private key. You must wait that platform to detect your deposit, its confirmations, and credit it to your account. #2: The address belongs to your another non custodial wallet. With this, you have private key, and you control your coin. Sometimes, even your transaction is confirmed, but if you have issues with wallet connections to nodes, servers, you might not see the confirmation. But because you have full control, you can configure your wallet and fix connection issues. With #1, if that exchange or online platform relies on, uses a Payment processor from another company like Bitpay, that has problems temporarily, you will not see your transaction, deposit credited to your account. Contact their support service to fix it. The company can wait for BitPay for example to fix problems and broadcast transactions, credit deposits automatically or the company can broadcast, credit it manually for users in waiting time of problem resolve from BitPay.

Payment processor has nothing to do with this, this doesn't involve crypto to fiat transfer or conversion of x crypto to y crypto. It's just moving Bitcoin from A to B and I guess OP meant crypto wallet as this platform cryptowallet which offers multiple services including buy/sell/swap but these detect the transactions as soon as it reaches certain number of confirmations which is generally varies from 2-6 on most. So OP sent funds with low fee which caused the delay and there is no point is speculating any further unless OP shares TXid or such details.

3 days ago, 17 sat/vbyte got confirmed but dropped to 6 sat/vbyte the same 3 days ago. I did not see the mempool get less congested below 4 sat/vbyte. Also, if 3 sat/vbyte is used, it is possible that the transaction would not have been confirmed by now.

Charles-Tim is right because I could remember that three days ago, I made a transaction from so many output as one input and I used 6sat/vbyte and it took only two hours for the confirmation. It means that OP used a fee that was very low. Although I was give a fee on 10sat/vbyte but I had to adjust it to 6sat/vbyte. I don't think OP is se ding from an exchange because exchange will not use a low transaction fee but a fee that will get your transaction confirmed first to build customer confidence in their service.

It can be a glitch from that mempool observer. What happened here? jochen-hoenicke.de [Confusing a website's mempool stats with the Bitcoin network] Checking with https://mempool.space/graphs/mempool#1w, mempools did not suddenly drop like that and I believe it is glitch or problem from full node used by https://jochen-hoenicke.de/queue/#0,1w. It dropped to nearly zero, not 5 or 6 sat/vbyte.

From the image that I posted above about https://jochen-hoenicke.de/queue/#BTC,24h,weight, the mempool did not drop to zero. It dropped to 6 sat/vbyte. Also if you check the site, the mempool did not drop more than 3 sat/vbyte during the time to during weekend. There was nothing that happened to https://jochen-hoenicke.de/queue/#BTC,24h,weight. Use the mouse the go through the mempool to understand what I mean.

I did not see that drop on mempool.space and the pattern of sudden drop is like issue reported in the past. If I see similar drop on another site like mempool.space, I will not think of that problem happened years ago. I did not say fee rate in mempools drop to 0 sat/byte with this glitch. Today if you use the site, you no longer see that glitch. It's actually a glitch.