How to avoid algebraic loops and to handle multiple delay units?

The following error is appearing while running a simulation environment for a Reinforcement Learning based UAV data gathering system:

Caused by:

Error using rl.env.SimulinkEnvWithAgent>localHandleSimoutErrors

(line 667)

Error due to multiple causes.

Error using

rl.env.SimulinkEnvWithAgent>localHandleSimoutErrors (line

667)

'envDQN/GD' or the model referenced by it contains a block

that updates persistent or state variables while computing

outputs and is not supported in an algebraic loop. It is in

an algebraic loop with the following blocks.

Error using

rl.env.SimulinkEnvWithAgent>localHandleSimoutErrors (line

667)

Input ports (12) of 'envDQN/GD' are involved in the loop.

Error using

rl.env.SimulinkEnvWithAgent>localHandleSimoutErrors (line

667)

Input ports (1) of 'envDQN/RL GD Chooser/AgentWrapper' are

involved in the loop. This message is related to a hidden

SignalConversion block.

This block is added for block 'envDQN/RL GD

Chooser/AgentWrapper' at input port 1 as result of block

insertion or expansion. The hidden block's parameter

'Output' is set to 'Signal copy' Consider manually inserting

such a block to debug the problem.

Error using

rl.env.SimulinkEnvWithAgent>localHandleSimoutErrors (line

667)

Input ports (3, 4) of 'envDQN/Energy Calculation' are

involved in the loop.

[Cris LaPierre]

One way to fix algebraic loops is to add a delay.

https://www.mathworks.com/help/simulink/ug/remove-algebraic-loops.html

[Arijit Bhattacharjee]

Thank you Cris for your help. The correct placement of the delay block resolved the issue.