Look, I’ve spent 25 years in a shop. You don't use a 3/8 drive when you need a 1/2 inch impact. Same logic applies to your electronics. If you want 45W speeds, you need the right hardware specs, not just a high number on the box. Listen, the S26 Plus relies on a protocol called PPS (Programmable Power Supply). This allows the charger to adjust voltage in small increments. This reduces heat. Heat is the enemy of any power cell. If the charger doesn't support the specific PPS profile for Samsung, it will throttle down to 25W or lower. Here is the breakdown for your setup:

• The Samsung 45W Power Adapter T4510 is the factory spec. It is designed to talk to the Samsung battery controller perfectly. It hits the 45W ceiling early in the charge cycle when the battery is low and tapers off correctly.
• The Anker 715 Charger Nano II 65W uses GaN technology. Gallium Nitride is more efficient than silicon. It runs cooler at high loads. It handles the 45W requirement easily because it has overhead, but you must verify it supports the 4.05A at 11V PPS profile.
• The cable is your fuel line. You must use a 5A (100W) rated USB-C to USB-C cable. Most standard cables are 3A. A 3A cable limits you to 25W regardless of the brick. Stick with the Samsung 45W Power Adapter T4510 and a 5A cable. It matches the internal resistance specs and keeps the thermals within the safe operating range. Don't buy knock-offs to save ten bucks.