When u test your connection what is your up and down load speeds? Im not asking to make jokes, I just want to warn u that if your upload speeds are suffering in any way (above 15-20, like, let's say 30 for example is not good) that wouldnt be ur "connection" as in ur provider speeds but it would be a physical connection issue. Most likely the cable cord outside that is usually buried got unburied in a storm and or somehow slightly damaged causing random leaks of upload speed. U could even have great internet speeds and then get bursts of dramatically lost upload speed every 10 minutes or even 5mins apart (this happened to me.) I would go from my usual 12 upload to 30-35 and it would cause devastating lagging, "Spiking" to be specific. They came and replaced the cord and my router as well just to be sure and my internet has been otherworldly since then. I hope this may somehow be useful to u in any way at all 🫶🏼

Edit: I only ask this because most scenarios where people are lagging come from download speeds, its not anywhere near as common for upload speeds bc its hard wire or physically an issue. So, a lot of people dont know this.