It isn't normal.
1 Have you checked the transmission fluid level?
2 Have you ever had the transmission fluid changed?
3 If 'overdrive' is actually 'torque converter lockup', it could be a solenoid, a control module issue, or the lockup clutch.
Sherm & Terry w/rescue Eydie (min Schnauzer) & Charley (std Poodle)
2015 Jay Flight 27RLS, GY Endurance (E), Days: 102 '15, 90 '16, 80 '17, 161 '18
2006 Ford F350 PSD, 4WD, CC, LB, SRW, Cmpr. pkg, Equal-i-zer 4-p, Continental ContiTrac TR