Recently I have started feeling like I am having a hypoglycemic event about 20 minutes in to a ride regardless of type or timing of food. Lightheadedness, feeling hot, and overall bonking feel are the symptoms. I have tried varying pre-ride fuel, timing and drinking on the bike. The 20-25 minute mark are usually when the symptoms start. They last about 15-20 minutes. Any suggestions are greatly appreciated.
Could be worth investing in one of these https://www.supersapiens.com/. Confirm the feelings are associated with the glucose level. Then work on strategies (LCHF, etc) to alleviate and develop a more stable daily profile. Definitely not something you want to leave too long without addressing.
Any history of hypoglycemia? How do these symptoms align with heart rate and respiration? Are your hands shaking? Legs feel weak? Please do not push through an episode especially when you feel lightheaded, as that could lead to a crash. Maybe you are going too hard too soon. Your aerobic engine needs time to get turning over. Until it is spun up your body fills in with more anaerobic power, so you might be burning off too much glycogen and when that happens your brain insists you slow down. Everyone is different in this regard. Try a longer, more gradual warm-up. Less sugar in your fuel for the first thirty minutes to an hour as the sugar can trigger a glucose spike and drop. Eating a candy bar just before the ride starts is an old hack that may not be right for you. Good luck!