Transactions stuck

I tried to spend some USDT from Metamask, but it never went thru, when i click the Tx Hash, it said transaction NOT found (my USDT never sent)…
I suspect it is due to previous transactions that never went thru (Contract Interaction), and being QUEUEd, i tried to cancel those queued tx, but also failed (nothing happened) … I always select FASTEST processing time with highest gas fee.
So:

  • Most of the times i am always stuck with transaction, even setting with high gas fee, why?
  • How do i solve my current issues, i can not even send my usdt out?
  • is it because of the queue, how to clear them? The queue is actually NOT a real queue waiting to excecute my transaction in the blockchain, otherwise it will show up when i etherscan it… Other wallets don’t have those kind of issues (queue).
  • I am using Metamask Chrome Ext.

Please advise / help.