You cut down and sanded your bermuda last year, right? I really prefer a reel mower on bermuda. What I am seeing is what happens when a rotary blade lifts up and cuts off stolons. The only time I do not object to a rotary on bermuda is when it is being used to scalp and thin bermuda because it does a good job of vacuuming up the debris. Otherwise, I like a 7 blade reel with the blades set for slight contact, a relief ground into the blades and a height of cut between 3/4-1". Low mowing with a reel tends to take care of a lot of weeds on account of the low cut and how the bermuda grows more dense. Likewise, for general trimming and mowing of places too steep for a reel, I prefer a trimming head that uses counter rotating blades rather than string. Same reason, string tears out the bermuda stolons. The local lawn guys use string trimmers to scalp down overgrown lawns. It is hard to say what kind of and quantity of fertilizer without a soil test indicating pH, phosphorus, potassium, calcium, magnesium, salinity, and micronutrient levels.
They who can give up essential liberty to obtain a little temporary safety, deserve neither liberty nor safety.
Benjamin Franklin 1775
Sell not virtue to purchase wealth, nor Liberty to purchase power.
Benjamin Franklin Poor Richard's Almanac1738