The issue new players / returning players / low level players have is that Blizzard introduced bonuses to Paragon gain for heroes that are below the server’s paragon level. The further below the server’s level that the hero is, the larger that bonus is, until I believe the current maximum bonus you can receive is a 1500% bonus to XP earned.
The base rate of XP for gaining a Battle Pass level is just under 1 million XP. With a 1500% XP bonus this means each Battle Pass level will grant just under 16 million XP. A full week’s Battle Pass will get you 13 Battle Pass levels. That’s 13 * 16 million XP = 208 million XP. Each Paragon level takes 3.5 million XP to gain. That means, just from the Battle Pass levels, you’ll gain over 59 paragon levels. Add in the XP you’re getting from mob kills, quests, Shadow weeklies, bonus Battle Pass points from events, Elder Rifts, Hidden Lairs, dungeons and so on, a hero with this level of XP bonus could easily gain 100 paragon levels in a week.
Back when the game was released, getting from Paragon 1 to 100 would have taken a hero 10 weeks. During those 10 weeks they would have farmed 10 weeks’ worth of gear / upgrades. Now that’s being condensed into 1 week’s worth of gear / upgrades. You are bound to find less gear / upgrades, because your Paragon level is far outstripping your ability to gain gear.
You will hit a point where, even though you have sufficient Paragon levels to move up to a higher difficulty level, you do not have sufficient Combat Rating to do so. That’s the point where you’re supposed to stay at that difficulty level for a while and farm gear / upgrades to catch up to your paragon level.
Is this an issue? Sure.
Is this a bug? No.
Show some examples, with screenshots of gear items you’re getting and what paragon level you are…