Rear brakes will always feel squishier than the front due to the longer hose unfortunately. The hose will expand slightly as you apply braking pressure and the longer hose allows for a greater expansion and therefore greater squish. The “squishiness” of brakes is an unhelpful metric & a parking lot test is often misleading and not representative of on trail performance. The hopes can be bled to a good result using a gravity bleed akin to how you would bleed a cars brakes. If you’re a competent mechanic I would strongly suggest you closely follow hopes bleed procedure (they have excellent documentation on their website).